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https://www.cazypedia.org/api.php?action=feedcontributions&feedformat=atom&user=Yann+Mathieu CAZypedia - User contributions [en-ca] 2026-04-30T13:18:33Z User contributions MediaWiki 1.35.10 https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16337 User:Yann Mathieu 2021-10-14T18:13:02Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> Yann Mathieu obtained his MsC in Protein Engineering in 2009 from the Université de Lorraine and completed his PhD in 2012 under the supervision of Eric Gelhaye and Marc Buée at the Université de Lorraine in the Tree-Microbe Interactions research unit. This work looked at the ecological and functional diversity of wood decomposing fungi and how the substrate influences their communities, their secreted biomass degrading enzymes <cite>#Mathieu2013</cite> and their detoxification enzymes <cite>Morel2013 </cite> with a focus on glutathione S-transferases and their structure-function relationship <cite>Mathieu2012 Mathieu2013b</cite>.<br /> <br /> He then moved to the south of France in Marseille to work as a post-doctoral scientist, in the Fungal Biodiversity and Biotechnology Laboratory, studying fungal oxidoreductases such as GMC-oxidoreductases [[AA3]] <cite>Piumi2014 Mathieu2016 Couturier2016</cite> and lytic polysaccharide monooxygenases [[AA9]] and their role in biomass degradation <cite>Garajova2016</cite>.<br /> <br /> After 2 years in Marseille, he moved to Vancouver at the University of British Columbia in Vancouver to pursue his work on fungal oxidoreductases within Harry Brumer's group where his research focuses on the screening, production, characterisation and structure-function relationship of lytic polysaccharide monooxygenases [[AA9]] <cite>Li2021</cite> and copper radical oxidases [[AA5]]_2 to better understand their substrate scope <cite>Mollerup2019</cite>, physiological roles and their applications in biocatalysis <cite>Mathieu2020</cite>.<br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Morel2013 pmid=23279857<br /> #Mathieu2013 pmid=23206919<br /> #Mathieu2012 pmid=23007392<br /> #Mathieu2013b pmid=24278272<br /> #Piumi2014 pmid=24965558<br /> #Mathieu2016 pmid=26873317<br /> <br /> #Couturier2016 pmid=26452496<br /> #Garajova2016 pmid=27312718<br /> #Mollerup2019 pmid=31091286<br /> <br /> #Li2021 pmid=33485381<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, 10(5), 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16336 User:Yann Mathieu 2021-10-14T18:12:32Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> Yann Mathieu obtained his MsC in Protein Engineering in 2009 from the Université de Lorraine and completed his PhD in 2012 under the supervision of Eric Gelhaye and Marc Buée at the Université de Lorraine in the Tree-Microbe Interactions research unit. This work looked at the ecological and functional diversity of wood decomposing fungi and how the substrate influences their communities, their secreted biomass degrading enzymes <cite>#Mathieu2013</cite> and their detoxification enzymes <cite>Morel2013 </cite> with a focus on glutathione S-transferases and their structure-function relationship <cite>Mathieu2012 Mathieu2013b</cite>.<br /> <br /> He then moved to the south of France in Marseille to work as a post-doctoral scientist, in the Fungal Biodiversity and Biotechnology Laboratory, studying fungal oxidoreductases such as GMC-oxidoreductases [[AA3]] <cite>Piumi2014 Mathieu2016 Couturier2016</cite> and lytic polysaccharide monooxygenases [[AA9]] and their role in biomass degradation <cite>Garajova2016</cite>.<br /> <br /> After 2 years in Marseille, he moved to Vancouver at the University of British Columbia in Vancouver to pursue his work on fungal oxidoreductases within Harry Brumer's group where his research focuses on the screening, production, characterisation and structure-function relationship of lytic polysaccharide monooxygenases [[AA9]] <cite>Li2021</cite> and copper radical oxidases [[AA5]]_2 to better understand their substrate scope <cite>Mollerup2019</cite>, physiological roles and their applications in biocatalysis <cite>Mathieu2020</cite>.<br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Gilbert2008 pmid=18430603<br /> #Morel2013 pmid=23279857<br /> #Mathieu2013 pmid=23206919<br /> #Mathieu2012 pmid=23007392<br /> #Mathieu2013b pmid=24278272<br /> #Piumi2014 pmid=24965558<br /> #Mathieu2016 pmid=26873317<br /> <br /> #Couturier2016 pmid=26452496<br /> #Garajova2016 pmid=27312718<br /> #Mollerup2019 pmid=31091286<br /> <br /> #Li2021 pmid=33485381<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, 10(5), 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16310 Auxiliary Activity Family 5 2021-10-12T18:03:02Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzymes catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have substrate specificities similar to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the hydroxyl group of diverse aliphatic and aromatic primary alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high catalytic efficiency towards 1-butanol, 2,4-hexadiene-1-ol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the pathogenic fungi ''Pyricularia oryzae'' (''Por''AlcOx) and ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is reproduced from <cite>Yin2015</cite> (CC BY 4.0).]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is reproduced from <cite>Yin2015</cite> (CC BY 4.0).]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16302 Auxiliary Activity Family 5 2021-09-28T23:44:43Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have substrate specificities similar to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the hydroxyl group of diverse aliphatic and aromatic primary alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high catalytic efficiency towards 1-butanol, 2,4-hexadiene-1-ol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the pathogenic fungi ''Pyricularia oryzae'' (''Por''AlcOx) and ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16301 Auxiliary Activity Family 5 2021-09-28T23:27:07Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have substrate specificities similar to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the hydroxyl group of diverse aliphatic and aromatic primary alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high catalytic efficiency towards 1-butanol, 2,4-hexadiene-1-ol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16300 Auxiliary Activity Family 5 2021-09-28T22:42:32Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have substrate specificities similar to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the hydroxyl group of diverse aliphatic and aromatic primary alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16299 Auxiliary Activity Family 5 2021-09-28T22:34:24Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have substrate specificities similar to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16298 Auxiliary Activity Family 5 2021-09-28T22:32:09Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx also includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16297 Auxiliary Activity Family 5 2021-09-28T22:29:10Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and in some instances can also oxidize the aldehyde into the corresponding acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16296 Auxiliary Activity Family 5 2021-09-28T22:23:31Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distantly related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the GlxA deletion mutant from ''Streptomyces lividans'' showed a loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and less often the acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16295 Auxiliary Activity Family 5 2021-09-28T22:19:46Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains characterized galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distably related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the deletion mutant of GlxA from ''Streptomyces lividans'' showed loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and less often the acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16293 Auxiliary Activity Family 5 2021-09-15T23:52:08Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distably related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the deletion mutant of GlxA from ''Streptomyces lividans'' showed loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and less often the acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidase (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Since these enzymes exhibited high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''Colletotrichum higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> while other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. <br /> <br /> The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while their ability to oxidize linear and aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex via the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have a reduction potential around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of these two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of AA5 enzymes is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2 enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5s share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> for the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not possess any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domain's involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. '''19''', 1580-1589. https://doi.org/10.1021/acs.oprd.5b00278<br /> <br /> #Forget2020 pmid=32108208<br /> <br /> #Johnson2021 pmid=33533375<br /> <br /> #Chaplin2015 pmid=26205496<br /> <br /> #Chaplin2017 pmid=28093470<br /> #Sola2019 pmid=30852555<br /> <br /> <br /> #Rosatella2011 Rosatella AA, Simeonov SP, Frade RFM, Afonso CAM. (2011) 5-Hydroxymethylfurfural (HMF) as a building block platform: Biological properties, synthesis and synthetic applications. Green Chem. '''13''', 754-93. https://doi.org/10.1039/C0GC00401D<br /> <br /> #Sousa201 Sousa AF, Vilela C, Fonseca AC, Matos M, Freire CSR, Gruter G-JM, Coelho JFJ, Silvestre AJD. (2015) Biobased polyesters and other polymers from 2,5-furandicarboxylic acid: a tribute to furan excellency. Polym Chem. '''6''', 5961-83. https://doi.org/10.1039/C5PY00686D<br /> <br /> #Yalpani1982 Yalpani, M.; Hall, L. D., (1982) Some chemical and analytical aspects of polysaccharide modifications. II. A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=Auxiliary_Activity_Family_5&diff=16292 Auxiliary Activity Family 5 2021-09-15T21:37:30Z

<p>Yann Mathieu: </p> <hr /> <div><br /> {{UnderConstruction}}<br /> * [[Author]]: ^^^Maria Cleveland^^^ and ^^^Yann Mathieu^^^<br /> * [[Responsible Curator]]: ^^^Harry Brumer^^^<br /> ----<br /> <br /> <br /> <div style="float:right"><br /> {| {{Prettytable}} <br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''Auxiliary Activity Family AA5'''<br /> |-<br /> |'''Fold''' <br /> |Seven-bladed β-propeller <br /> |-<br /> |'''Mechanism'''<br /> |Copper Radical Oxidase<br /> |-<br /> |'''Active site residues'''<br /> |known<br /> |-<br /> |{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''<br /> |-<br /> | colspan="2" |{{CAZyDBlink}}AA5.html<br /> |}<br /> </div><br /> <br /> <br /> == General Properties ==<br /> <br /> Enzymes from the CAZy family Auxiliary Activity 5 (AA5) are mononuclear copper-radical oxidases (CRO) that perform catalysis without complex organic cofactors such as FAD or NADP and use oxygen as their electron acceptor ([{{EClink}}1.1.3.- EC 1.1.3.-]). Family AA5 enzymes are classified in two subfamilies: subfamily AA5_1 contains characterized glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) <cite>Daou2017</cite> and subfamily AA5_2 contains galactose oxidases ([{{EClink}}1.1.3.9 EC 1.1.3.9]) <cite>Whittaker2003</cite>, as well as the more recently discovered raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite>, aliphatic alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.1.3.13]) <cite>Yin2015,Oide2019,Cleveland2021b</cite> and aryl alcohol oxidase ([{{EClink}}1.1.3.7 EC 1.1.3.7]) <cite>Mathieu2020;Cleveland2021a</cite>.<br /> <br /> The most studied enzyme in subfamily AA5_1 is the glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>. For subfamily AA5_2, the archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) was first reported in 1959 from cultures of ''Polyporus circinatus'' (later renamed ''Fusarium graminearum'' <cite>Ogel1994,Cooper1959</cite>. Until 2015, characterized enzymes from the AA5_2 subfamily were found to exhibit mainly galactose oxidase activity, but since then novel non-carbohydrate oxidase enzymes were found <cite>Yin2015,Oide2019,Mathieu2020,Cleveland2021a,Cleveland2021b</cite>.<br /> <br /> An AA5 enzyme from ''Arabidopsis thaliana'', whose sequence does not fall within the two known subfamilies, has been identified as a putative galactose oxidase, RUBY, and has been demonstrated to promote the cell-to-cell adhesion in the seed coat epidermis of Arabidopsis <cite>Sola2019 </cite>. Furthermore, an enzyme distably related to AA5 called GlxA, has been shown to have activity on glycolaldehyde and the deletion mutant of GlxA from ''Streptomyces lividans'' showed loss of glycan accumulation at hyphal tips <cite>Chaplin2015</cite>.<br /> == Substrate Specificities ==<br /> An important distinction between the AA5_1 and AA5_2 subfamilies, is that while AA5_1 enzyme catalyze the two-electron oxidation of simple aldehydes and hydroxycarbonyl <cite>Kersten2014</cite>, the AA5_2 members accept alcohol containing substrates and usually oxidatively form the corresponding aldehyde and less often the acid <cite>Whitaker2003,Parikka2015</cite>.<br /> <br /> ==== AA5_1 ====<br /> <br /> The AA5_1 enzymes have been characterized as glyoxal oxidases ([{{EClink}}1.2.3.15 EC 1.2.3.15]) and show activity on simple aldehydes, α-hydroxycarbonyl, and α-dicarbonyl compounds, with the highest activity observed on glyoxal, methyl glyoxal and glycolaldehyde <cite>Whittaker1996,Whitaker1999,Kersten1987,Leuthner2004,Kersten2014</cite>. In contrast, two glyoxal oxidases form ''Pycnoporus cinnabarinus'' demonstrate the highest catalytic efficiency on glyoxylic acid as the substrate <cite> Daou2016</cite>.<br /> <br /> ==== AA5_2 ====<br /> <br /> The founding member of AA5_2 from ''Fusarium graminearum'' is a galactose oxidases (''Fgr''GalOx), which catalyzes the regioselective oxidation of the C6-hydroxyl group on the monosaccharide galactose ([{{EClink}}1.1.3.7 EC 1.3.3.7]) <cite>Avigad1962</cite>. The range of substrates oxidized by ''Fgr''GalOx includes galactose derivatives such as 1-methyl-b-galactopyranoside <cite>Paukner2015</cite>, and galactose-containing oligo-and polysaccharides including: lactose, melibiose, raffinose, galactoxyloglucan, galactomannan and galactoglucomannan <cite>Parikka2015,Parikka2010</cite>. Most other AA5_2s from the ''Fusarium'' family, such as ''F. oxysporum'' <cite>Paukner2014</cite>, ''F. sambucinum'' <cite>Paukner2015</cite>, and ''F. acuminatum'' <cite>Alberton2007</cite> have similar substrate specificities to ''Fgr''GalOx.<br /> <br /> In 2015, two AA5_2 oxidases with distinct substrate profiles were discovered from ''Colletotrichum graminicola'' and ''Colletotrichum gloeosporioides'' (''Cgr''AlcOx and ''Cgl''AlcOx) that were essentially inactive on galactose and galactosides, but efficiently oxidized the primary hydroxyl of diverse aliphatic and aromatic alcohols <cite>Yin2015</cite>. Due to these enzymes exhibiting high specificity towards 1-butanol, benzyl alcohol and cinnamyl alcohol, they were classified as general alcohol oxidases ([{{EClink}}1.1.3.13 EC 1.3.3.13]) <cite>Yin2015</cite>. In addition, two alcohol oxidases were characterized from the rice blast pathogen ''Pyricularia oryzae'' (''Por''AlcOx) and from ''C.'' ''higginsianum'' (''Chi''AlcOx) with both enzymes showing prominent activity on n-butanol, ethanol, 1,3-butanediol and glycerol <cite>Oide2019</cite>. Since then, more AA5_2 enzymes from various fungal origins have been characterized as general alcohol oxidases, some being able to efficiently oxidize both carbohydrate and non-carbohydrate substrates (ex.''Afl''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> Furthermore, another AA5_2 member from ''C. graminicola'' has been characterized as an aryl-alcohol oxidase (''Cgr''AAO) due to its high specific activity towards substituted benzyl alcohols and 5-hydroxymethylfurfural (HMF) ([{{EClink}}1.1.3.7 EC 1.1.3.7] and [{{EClink}}1.1.3.47 EC 1.1.3.47]) <cite>Mathieu2020</cite>. In addition, two AA5_2 homologs from ''Fusarium'' species have been also classified as aryl alcohols oxidases (''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a</cite> and other AA5_2 members have been shown to have prominent activity on HMF with enzymes being able to fully oxidize the furan substrate to FDCA (''Gci''AlcOx) <cite>Cleveland2021b</cite>.<br /> <br /> The last distinct group of AA5_2 enzymes based on substrate specificity are the raffinose-specific oxidases ([{{EClink}}1.1.3.- EC 1.3.3.-]). These enzymes show only negligible activity on galactose, were not active towards aliphatic alcohols, however, they showed the highest activity for the tri-saccharide raffinose, the diol glycerol, and the glycolaldehyde dimer <cite>Andberg2017,Cleveland2021b</cite>.<br /> <br /> Hence, the AA5_2 family contains a diverse set of enzymes with galactose oxidases, raffinose oxidases, general alcohol oxidases (carbohydrate and non-carbohydrate) and aryl alcohol oxidases. The ability of CROs to oxidize galactose-containing sugars can be utilized for the production of biomaterials from biomass sources <cite>Yalpani1982,Kelleher1986,Schoevaart2004,Leppanen2014,Xu2012,Parikka2012,Mikkonen2014,Derikvand2016</cite> while the ability to oxidize aromatic alcohols to the corresponding aldehydes can be utilized in a variety of applications within the food and fragrance industry <cite>Ribeaucourt2021</cite>. Similarly, the ability of CROs to convert HMF into the bi-functional polymer precursors DFF and FDCA can be potentially utilized in the context of bio-polymer manufacturing <cite>Rosatella2011,Sousa2015</cite>.<br /> <br /> == Kinetics and Mechanism ==<br /> <br /> [[File:CRO_mechanism.png|thumb|400px|right|'''Figure 1.''' Reaction mechanism of copper radical oxidases. A. First half-reaction – oxidation of substrate. B. Second-half reaction – regeneration of active site radical. PT – proton transfer, HAT – hydrogen atom transfer, ET – electron transfer. This figure is adapted from <cite>Yin2015</cite>.]]<br /> AA5 enzymes oxidize their substrate with concurrent reduction of oxygen to hydrogen peroxide in a two-electron process mediated through a free-radical-coupled copper complex mediated through the presence of a redox active Tyr-Cys cofactor. In AA5_2 the Tyr-Cys cofactor exhibits an unusually low reduction potential (+275 mV) <cite>Cowley2016,Thomas2002,Wright2001</cite> compared to unmodified tyrosine in solution (> +800 mV) or in other enzymatic systems <cite>Itoh2000</cite>. Several factors could contribute to this phenomenon by increasing the stability of the protein free radical including π-stacking with aromatic residues and the electron donating effect of the thioether linkage <cite>Jazdzewski2000,Whittaker2003,Rogers2007</cite>. In contrast, AA5_1 have reduction potential of around +640 mV <cite>Whittaker1996</cite> which could explain the different oxidizing power of the two subfamilies <cite>Wright2001,Kersten2014</cite>. One reason for the higher reduction potential of glyoxal oxidases could be subtitution of the secondary shell amino acid Trp in AA5_2 with a His in AA5_1 <cite>Wright2001,Kersten2014</cite>. In the archetypal AA5_2 member, ''Fgr''GalOx, the Trp290His substitution increased the reduction potential of the resulting enzyme from +400 mV to +730 mV <cite>Saysell1997</cite>; however, it also decreased the catalytic efficiency by 1000-fold <cite>Baron1994</cite> and affected the stability of the [Cu2+ Tyr·] metallo-radical complex at neutral pH <cite>Rogers1998</cite>. ''Cgr''AlcOx and ''Cgr''AAO have been speculated to have a lower reduction potential than ''Fgr''GalOx due to their secondary shell amino acid substitutions (Phe in ''Cgr''AlcOx and Tyr in ''Cgr''AAO) <cite>Yin2015,Mathieu2020</cite>.<br /> <br /> A substantial amount of spectroscopic evidence has supported a ping-pong mechanism for AA5 enzymes <cite>Whittaker2003,Whittaker2005,Baron1994,Humphreys2009,Whittaker1993,Whittaker1996,Whittaker1999,Kersten2014</cite>, including some theoretical and biomimetic models possessing mechanistic similarities <cite>Wang1998,Himo2000</cite>. The reaction progresses through a two-step process: the first half-reaction performs the oxidation of the substrate, while the second half-reaction regenerates the oxidation state of the active-site copper with concurrent reduction of molecular oxygen to hydrogen peroxide. Each half reaction consists of three steps: proton transfer (PT), hydrogen atom transfer (HAT), and an electron transfer (ET).<br /> <br /> Other work, focused on optimizing the industrial potential of AA5 enzymes, has shown that AA5_2 enzymes have increased activity with the addition of peroxidases (horse-radish peroxidase and catalase) and small molecule activators (potassium ferricyanide and magnesium (III) acetate) <cite>Cleveland1975,Hamilton1978,Pedersen2015,Forget2020,Johnson2021</cite>.<br /> <br /> == Catalytic Residues ==<br /> <br /> [[File: FgrGalOx_Active_site_CAZY.png|thumb|250px|right|'''Figure 2.''' Active site residues of copper radical oxidases FgrGalOx, Cu ion in orange (PDB ID [{{PDBlink}}1gof 1GOF]). ]]<br /> <br /> The redox-active center of AA5 oxidases comprises a copper ion that is stabilized by two tyrosines and two histidines (in ''Fgr''GalOx, these are Tyr272, Tyr495, His496, His581), resulting in a distorted square pyramidal geometry <cite>Whittaker1996,Whittaker1999,Whittaker2003,Whittaker2005</cite>. Based on the copper coordination environment, AA5 proteins are type 2 “non-blue” copper category due to the nitrogen and oxygen ligands <cite>Ito1994</cite>.<br /> The unique feature of the AA5 is the covalently linked equatorial tyrosine with an adjacent cysteine by a thioether bond (Tyr 272 and Cys 228 in the archetypal ''Fgr''GalOx) <cite>Ito1991,Ito1994</cite>. The thioether linkage forms spontaneously in the presence of copper and has been shown to stabilize the radical though delocalization that forms on the equatorial tyrosine during catalysis <cite>Rogers2008</cite>.<br /> <br /> Another important feature of AA5 enzymes is a secondary shell amino acid that is located on top of the tyrosine-cysteine cofactor. It has been speculated to be critical in determining the substrate specificity, radical stability and redox activity by hydrogen bonding, delocalization and/or by protecting the thioether bond from solvent <cite>Whittaker2003,Rogers2007,Kersten2014, Daou2017</cite>. This residue in AA5_1, based on sequence alignments, has been conserved as a histidine <cite>Kersten2014</cite>, while characterized AA5_2s enzymes have an aromatic residue at this position: a tryptophan in galactose oxidases (W290 in ''Fgr''GalOx) <cite>Rogers2007,Cleveland2021b</cite>, a phenylalanine in the ''Colletotrichum'' aliphatic alcohol oxidases <cite>Yin2015</cite>, whereas a tyrosine is present in the raffinose oxidases <cite>Andberg2017,Cleveland2021b</cite> and aryl alcohol oxidase from ''Colletotrichum graminicola'' <cite>Mathieu2020</cite>. Furthermore, an AA5 enzyme from ''Streptomyces lividans'' with activity on glycolaldehyde possesses a tryptophan as the stacking secondary shell residue whose indole ring is oriented differently compared to ''Fgr''GalOx, which may affect the substrate specificity <cite>Chaplin2015,Chaplin2017</cite>. <br /> <br /> == Three-dimensional Structures ==<br /> <br /> [[File:CRO_tertiary_structure.png|thumb|400px|right|'''Figure 3.''' Crystal structure of copper radical oxidases. A. ''Fgr''GalOx (PDB ID [{{PDBlink}}1gof 1GOF]), Copper ion in orange and B. ''Cgr''AlcOx (PDB ID [{{PDBlink}}5c86 5C86]), Copper ion in grey. This figure is adapted from <cite>Yin2015</cite>.]]<br /> <br /> AA5 share a seven-bladed β-propeller fold <cite>Ito1994,Yin2015,Mathieu2020</cite> as the catalytic domain containing the active site. The archetypal ''Fgr''GalOx contains three domains: domain 1 has a “β sandwich” structure identified as a carbohydrate binding module ([[CBM32]]) with affinity for galactose, domain 2 is the catalytic domain and domain 3 is the smallest, which forms a hydrogen bonding network to stabilize domain 2 <cite>Ito1994</cite>. Other characterized AA5_2 enzymes from ''Fusarium'' species contain [[CBM32]] <cite>Paukner2014,Paukner2015,Faria2019,Cleveland2021b</cite>, even though some do not display canonical galactose oxidase activity (ex. ''Fgr''AAO and ''Fox''AAO) <cite>Cleveland2021a,Cleveland2021b</cite>.<br /> In contrast, ''Cgr''AlcOx, ''Cgl''AlcOx and ''Chi''AlcOx do not poses any CBM <cite>Yin2015,Oide2019</cite>, while ''Cgr''AAO and ''Cgr''RafOx have a PAN domain present instead <cite>Mathieu2020,Andberg2017</cite>. ''Por''AlcOx contained a WSC domain that was able to bind xylans and fungal chitin/β-1,3-glucan, implicating the domains involvement in enzyme anchoring on the plant surface <cite>Oide2019</cite>. In addition, the fusion of a galactose oxidase with a CBM29 has shown to increase the catalytic efficiency of the construct on galactose-containing hemicelluloses compared to WT <cite>Mollerup2016</cite>.<br /> <br /> == Family Firsts ==<br /> <br /> ;First AA5_1 enzyme discovered: The glyoxal oxidase from ''Phanerochaete chrysosporium'' discovered in 1987 <cite>Kersten1987</cite>.<br /> <br /> ;First AA5_2 enzyme discovered: The archetypal galactose-6 oxidase from ''Fusarium graminearum'' (''Fgr''GalOx) discovered in 1959 <cite>Cooper1959</cite>.<br /> <br /> ;Copper requirement confirmed: While this first report already established FgrGalOx as a metalloenzyme; its copper requirement was later confirmed <cite>Amaral1963</cite>.<br /> <br /> ;First 3-D structure: The first crystallography structure of AA5 was of the archetypal ''Fgr''GalOx in 1991 <cite>Ito1991</cite>.<br /> <br /> == References ==<br /> <biblio><br /> <br /> #Andberg2017 pmid=28778886<br /> <br /> #Yin2015 pmid=26680532<br /> <br /> #Oide2019 pmid=30885320<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, '''10''', 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> #Kersten1987 pmid=3553159<br /> #Ogel1994 Ögel, Z. B.; Brayford, D.; McPherson, M. J., (1994). Cellulose-triggered sporulation in the galactose oxidase-producing fungus Cladobotryum (Dactylium) dendroides NRRL 2903 and its re-identification as a species of Fusarium. Mycol. Res., '''98''', 474-480. https://doi.org/10.1016/j.pep.2014.12.010<br /> #Cooper1959 pmid=13641238<br /> #Amaral1963 pmid=14012475<br /> #Cleveland2021a pmid=34134727<br /> <br /> #Cleveland2021b pmid=<br /> #Paukner2014 pmid=24967652<br /> #Paukner2015 pmid=25543085<br /> #Faria2019 pmid=31177409<br /> <br /> #Ito1994 pmid=8182749<br /> <br /> #Mollerup2016 pmid=26858983<br /> <br /> #Daou2017 pmid=28390013<br /> #Ito1991 pmid=2002850<br /> <br /> #Cowley2016 pmid=27626829<br /> <br /> #Thomas2002 pmid=12203454<br /> <br /> #Whittaker1993 pmid=8386015<br /> <br /> #Wright2001 pmid=11551381<br /> <br /> #Itoh2000 Itoh, S.; Taki, M.; Fukuzumi, S., (2000). Active site models for galactose oxidase and related enzymes. Coord. Chem. Rev. '''198''', 3-20. https://doi.org/10.1016/S0010-8545(99)00209-X<br /> <br /> #Jazdzewski2000 Jazdzewski, B. A.; Tolman, W. B., (2000). Understanding the copper–phenoxyl radical array in galactose oxidase: contributions from synthetic modeling studies. Coord. Chem. Rev. '''200-202''', 633-685. https://doi.org/10.1016/S0010-8545(00)00342-8<br /> <br /> #Whittaker2003 pmid=12797833<br /> <br /> #Rogers2007 pmid=17385891<br /> <br /> #Whittaker1996 pmid=8557673<br /> <br /> #Kersten2014 pmid=24915038<br /> <br /> #Baron1994 pmid=7929198<br /> <br /> #Saysell1997 Saysell, C. G.; Barna, T.; Borman, C. D.; Baron, A. J.; McPherson, M. J.; Sykes, A. G., P(1997). Properties of the Trp290His variant of Fusarium NRRL 2903 galactose oxidase: interactions of the GOasesemi state with different buffers, its redox activity and ability to bind azide. J. Biol. Inorg. Chem. '''2''', 702-709. https://doi.org/10.1007/s007750050186<br /> <br /> #Rogers1998 Rogers, M. S.; Knowles, P. F.; Baron, A. J.; McPherson, M. J.; Dooley, D. M., (1998). Characterization of the active site of galactose oxidase and its active site mutational variants Y495F/H/K and W290H by circular dichroism spectroscopy. Inorg. Chim. Acta. '''275-276''', 175-181. https://doi.org/10.1016/S0020-1693(97)06142-2<br /> <br /> #Whittaker1999 pmid=10593910<br /> <br /> #Whittaker2005 pmid=15581579<br /> <br /> #Humphreys2009 pmid=19290629<br /> <br /> #Wang1998 pmid=9438841<br /> <br /> #Himo2000 Himo, F.; Eriksson, L. A.; Maseras, F.; Siegbahn, P. E. M., (2000). Catalytic Mechanism of Galactose Oxidase: A Theoretical Study. J. Am. Chem. Soc. '''122''', 8031-8036. https://doi.org/10.1021/ja994527r<br /> <br /> #Cleveland1975 pmid=164209<br /> <br /> #Hamilton1978 pmid=183480<br /> <br /> #Pedersen2015 Toftgaard Pedersen, A.; Birmingham, W. R.; Rehn, G.; Charnock, S. J.; Turner, N. J.; Woodley, J. M., (2015) Process Requirements of Galactose Oxidase Catalyzed Oxidation of Alcohols. Org. Process Res. Dev. 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A high-yielding, specific method for the chemical derivatization of galactose-containing polysaccharides: Oxidation with galactose oxidase followed by reductive amination. J. Polym. Sci., Polym. Chem. Ed. '''20''', 3399-3420. https://doi.org/10.1002/pol.1982.170201213<br /> <br /> #Kelleher1986 pmid=3791303<br /> <br /> #Schoevaart2004 Schoevaart, R.; Kieboom, T., (2004) Application of Galactose Oxidase in Chemoenzymatic One-Pot Cascade Reactions Without Intermediate Recovery Steps. Top. Catal. '''27''', 3-9. https://doi.org/10.1023/B:TOCA.0000013536.27551.13<br /> <br /> #Leppanen2014 pmid=24188837<br /> <br /> #Xu2012 pmid=22422625<br /> <br /> #Parikka2012 pmid=22724576<br /> <br /> #Mikkonen2014 Mikkonen, K. S.; Parikka, K.; Suuronen, J.-P.; Ghafar, A.; Serimaa, R.; Tenkanen, M., (2014) Enzymatic oxidation as a potential new route to produce polysaccharide aerogels. RSC Advances. '''4''', 11884-11892. https://doi.org/10.1039/C3RA47440B<br /> <br /> #Derikvand2016 pmid=26892369<br /> <br /> #Alberton2007 pmid=17518413<br /> <br /> #Parikka2010 pmid=20000571<br /> <br /> #Parikka2015 Parikka, K.; Master, E.; Tenkanen, M., (2015) Oxidation with galactose oxidase: Multifunctional enzymatic catalysis. J. Mol. Catal. B: Enzym. '''120''', 47-59. https://doi.org/10.1016/j.molcatb.2015.06.006<br /> <br /> #Ribeaucourt2021 pmid=34147589<br /> <br /> #Daou2016 pmid=27260365<br /> <br /> #Leuthner2004 pmid=15578222<br /> <br /> #Kersten1990 pmid=11607073<br /> #Rogers2008 pmid=18771294<br /> <br /> </biblio><br /> <br /> [[Category:Auxiliary Activity Families|AA005]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16257 User:Yann Mathieu 2021-09-07T22:36:33Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> Yann Mathieu obtained his MsC in Protein Engineering in 2009 from the Université de Lorraine and completed his PhD in 2012 under the supervision of Eric Gelhaye and Marc Buée at the Université de Lorraine in the Tree-Microbe Interactions research unit. This work looked at the ecological and functional diversity of wood decomposing fungi and how the substrate influences their communities, their secreted biomass degrading enzymes <cite>#Mathieu2013</cite> and their detoxification enzymes <cite>#Morel2013 </cite> with a focus on glutathione S-transferases and their structure-function relationship <cite>#Mathieu2012 #Mathieu2013b</cite>.<br /> <br /> He then moved to the south of France in Marseille to work as a post-doctoral scientist, in the Fungal Biodiversity and Biotechnology Laboratory, studying fungal oxidoreductases such as GMC-oxidoreductases AA3 <cite>#Pimui2014 #Mathieu2016 #Couturier2016</cite> and lytic polysaccharide monooxygenases AA9 and their role in biomass degradation <cite>#Garajova2016</cite>.<br /> <br /> After 2 years in Marseille, he moved to Vancouver at the University of British Columbia in Vancouver to pursue his work on fungal oxidoreductases within Harry Brumer's group where his research focuses on the screening, production, characterisation and structure-function relationship of lytic polysaccharide monooxygenases AA9 <cite>#Li2021</cite> and copper radical oxidases AA5_2 to better understand their substrate scope <cite>#Mollerup2019</cite>, physiological roles and their applications in biocatalysis <cite>#Mathieu2020</cite>.<br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Gilbert2008 pmid=18430603<br /> #Morel2013 pmid=23279857<br /> #Mathieu2013 pmid=23206919<br /> #Mathieu2012 pmid=23007392<br /> #Mathieu2013b pmid=24278272<br /> #Piumi2014 pmid=24965558<br /> #Mathieu2016 pmid=26873317<br /> <br /> #Couturier2016 pmid=26452496<br /> #Garajova2016 pmid=27312718<br /> #Mollerup2019 pmid=31091286<br /> <br /> #Li2021 pmid=33485381<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, 10(5), 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16256 User:Yann Mathieu 2021-09-07T22:36:11Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> '''This is an empty template to help you get started with composing your User page.'''<br /> <br /> Yann Mathieu obtained his MsC in Protein Engineering in 2009 from the Université de Lorraine and completed his PhD in 2012 under the supervision of Eric Gelhaye and Marc Buée at the Université de Lorraine in the Tree-Microbe Interactions research unit. This work looked at the ecological and functional diversity of wood decomposing fungi and how the substrate influences their communities, their secreted biomass degrading enzymes <cite>#Mathieu2013</cite> and their detoxification enzymes <cite>#Morel2013 </cite> with a focus on glutathione S-transferases and their structure-function relationship <cite>#Mathieu2012 #Mathieu2013b</cite>.<br /> <br /> He then moved to the south of France in Marseille to work as a post-doctoral scientist, in the Fungal Biodiversity and Biotechnology Laboratory, studying fungal oxidoreductases such as GMC-oxidoreductases AA3 <cite>#Pimui2014 #Mathieu2016 #Couturier2016</cite> and lytic polysaccharide monooxygenases AA9 and their role in biomass degradation <cite>#Garajova2016</cite>.<br /> <br /> After 2 years in Marseille, he moved to Vancouver at the University of British Columbia in Vancouver to pursue his work on fungal oxidoreductases within Harry Brumer's group where his research focuses on the screening, production, characterisation and structure-function relationship of lytic polysaccharide monooxygenases AA9 <cite>#Li2021</cite> and copper radical oxidases AA5_2 to better understand their substrate scope <cite>#Mollerup2019</cite>, physiological roles and their applications in biocatalysis <cite>#Mathieu2020</cite>.<br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Gilbert2008 pmid=18430603<br /> #Morel2013 pmid=23279857<br /> #Mathieu2013 pmid=23206919<br /> #Mathieu2012 pmid=23007392<br /> #Mathieu2013b pmid=24278272<br /> #Piumi2014 pmid=24965558<br /> #Mathieu2016 pmid=26873317<br /> <br /> #Couturier2016 pmid=26452496<br /> #Garajova2016 pmid=27312718<br /> #Mollerup2019 pmid=31091286<br /> <br /> #Li2021 pmid=33485381<br /> #Mathieu2020 Mathieu, Y., Offen, W. A., Forget, S. M., Ciano, L., Viborg, A. H., Blagova, E., Henrissat, B., Walton, P.H, Davies, G.J, and Brumer, H. (2020). Discovery of a fungal copper radical oxidase with high catalytic efficiency toward 5-hydroxymethylfurfural and benzyl alcohols for bioprocessing. ACS Catalysis, 10(5), 3042-3058. https://pubs.acs.org/doi/abs/10.1021/acscatal.9b04727<br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16255 User:Yann Mathieu 2021-09-07T21:13:56Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> '''This is an empty template to help you get started with composing your User page.'''<br /> <br /> Yann Mathieu obtained his MsC in Protein Engineering in 2009 from the Université de Lorraine and completed his PhD in 2012 under the supervision of Eric Gelhaye and Marc Buée at the Université de Lorraine. This work looked at the ecological and functional diversity of wood decomposing fungi and how the substrate influences their communities and their detoxification enzymes with a focus on glutathione S-transferases and their structure-function relationship cite #Morel2013.<br /> He then <br /> <br /> <br /> <br /> <br /> ''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''<br /> <br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Gilbert2008 pmid=18430603<br /> #Morel2013 pmid=23279857<br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=User:Yann_Mathieu&diff=16254 User:Yann Mathieu 2021-09-07T19:09:18Z

<p>Yann Mathieu: </p> <hr /> <div>[[Image:YannMathieu.jpg|200px|right]]<br /> '''This is an empty template to help you get started with composing your User page.'''<br /> <br /> You should begin by opening this page for editing by clicking on the Edit tab above. Your biography goes in this area of the page.<br /> <br /> * See [[User:Gerlind_Sulzenbacher]] for an example. You may copy text from this example by opening the page in another browser window and clicking the "Edit" tab.<br /> * Add your publications in the list below using PubMed IDs and cite them in the text like this <cite>Gilbert2008</cite>.<br /> * Please upload a picture of yourself using the "Upload file" link in the Toolbox section of the left menu, and then replace the Image filename with your own.<br /> <br /> ''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''<br /> <br /> <br /> <br /> ----<br /> <br /> <biblio><br /> #Gilbert2008 pmid=18430603<br /> <br /> </biblio><br /> <br /> <br /> [[Category:Contributors|Mathieu,Yann]]</div>

Yann Mathieu https://www.cazypedia.org/index.php?title=File:YannMathieu.jpg&diff=16253 File:YannMathieu.jpg 2021-09-07T19:08:09Z

<p>Yann Mathieu: </p> <hr /> <div></div>

Yann Mathieu