CAZypedia - User contributions [en-ca]

Glycoside Hydrolase Family 71

2026-01-23T08:34:48Z

Johan Larsbrink:

{{CuratorApproved}}
* [[Author]]: [[User:Antonielle Vieira Monclaro|Antonielle Vieira Monclaro]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH71'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|inverting
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH71.html
|}
</div>

[[File: AnGH71C.png|thumb|right|500px|'''Figure 1. Structure of ''An''GH71C from ''Aspergillus nidulans''.''' The structure solved with nigerooligosaccharides as ligand is shown (PDB ID [{{PDBlink}}9fnh 9FNH]), with one protein molecule and oligosaccharides from different chains that together span the active site, as blue sticks. The core catalytic (α/β)8 barrel is shown in silver, the C-terminal β-sheet domain in pale orange, and the catalytic residues in green.]]

== Substrate specificities ==

GH71 comprises enzymes with α-1,3-glucanase activity (EC 3.2.1.59), often referred to as mutanases, based on mutan being an alternative name for α-1,3-glucan (from ''Streptococcus mutans''). Early studies demonstrated that these enzymes hydrolyze pure α-1,3-glucans while remaining inactive toward α-glucans containing mixed α-1,3/α-1,4 linkages <cite>Zonneveld1972</cite>. Subsequent work showed that GH71 enzymes act on a broader range of α-1,3-linked glucans, including pseudonigeran and soluble carboxymethylated α-1,3-glucan, but display no activity toward other tested α- or β-linked glycans <cite>Imai1977 Fuglsang2000 VillalobosDuno2013 AitLahsen2001 Dekker2004 Mazurkewich2025</cite>.

Depending on the enzyme, GH71 α-1,3-glucanases may exhibit exo- or endo-type hydrolytic activity. Some enzymes with exo activity, such as Agn13.1 from ''Trichoderma harzianum'', showed a 1:1 correlation between glucose released and reducing sugars, typical of exo hydrolysis, and was unable to cleave periodate-oxidized S-glucan, which is resistant to exo-α-1,3-glucanases <cite>AitLahsen2001</cite>. Endo-acting GH71 enzymes include Agn1p from ''Schizosaccharomyces pombe'' which does not hydrolyze pNP-α-glucose, and is not inhibited by classical exo-glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, or D-glucono-1,5-lactone <cite>Dekker2004</cite>. MutAp from ''T. harzianum'', an endo-hydrolytic α-1,3-glucanase, is suggested to act processively from the non-reducing end, repeatedly releasing glucose before dissociating <cite>Grun2006 Sinitsyna2025</cite>. Its insensitivity to multiple exo-glycosidase inhibitors, and experiments with reduced oligosaccharides (e.g., G5-ol) further yield no products compatible with exo activity (e.g., G4-ol). The minimum chain-length requirement for MutAp has been shown to be a tetrasaccharide.

The ''Aspergillus nidulans'' enzymes AnGH71B and AnGH71C display distinct behaviors when acting on reduced oligosaccharides (nigeropentaose and nigerohexaose), reflecting different cleavage mechanisms <cite>Mazurkewich2025</cite>. AnGH71C exhibits a pattern consistent with endo-cleavage, evidenced by the diverse products generated from reduced nigerohexaose. In contrast, AnGH71B displays exo-processive characteristics despite the absence of released reduced glucose, explained by the inability of subsite +1 to accommodate the reduced unit and therefore preventing classical terminal cleavage.

Overall, GH71 enzymes exhibit strict specificity for continuous regions of α-1,3-glycosidic linkages, with no tolerance for alternating segments containing α-1,4 linkages <cite>Zonneveld1972 AitLahsen2001</cite>, as found in the polysaccharide nigeran (α-1,3/1,4-glucan). End products range from glucose (e.g. from endo-acting processive action), to nigerooligosaccharides with DP 2–7 <cite>VillalobosDuno2013 Dekker2004 Sinitsyna2025</cite>. Nigerotriose has been found as a final product together with glucose from endo-acting processive GH71 enzymes <cite>Mazurkewich2025 Grun2006</cite>.

== Kinetics and Mechanism ==
The anomeric configuration of the products released by α-1,3-glucanases has been elucidated by complementary NMR and crystallography approaches. In the case of MutAp from ''T. harzianum'', the hydrolysis of carboxymethylated α-1,3-glucan was monitored by ¹H NMR, revealing the appearance of β-Glc signals and the complete absence of α-Glc, demonstrating inversion of the anomeric configuration <cite>Grun2006</cite>. NMR studies of AnGH71B and AnGH71C from ''A. nidulans'' likewise showed inversion of products, and structures including the inverted anomer of the product nigerose further supports these findings <cite>Mazurkewich2025</cite>.

== Catalytic Residues ==
Three conserved acidic residues (Asp69, Asp237, and Glu240) were identified in the active site of Agn1p by Horaguchi et al. <cite>Horaguchi2025</cite>. Individual substitutions of these residues (D69N, D237A/N, E240A/Q) led to drastic reductions in activity on α-1,3-glucan.

Structure-guided mutational studies of AnGH71B and AnGH71C directly identified the catalytic residues Asp265 (general base) and Glu268 (general acid), functionally separating subsites −4 to +3 of the enzymes <cite>Mazurkewich2025</cite>. The simultaneous observation of the α-linked substrate nigerotetraose and β-anomer of nigerotriose as product in the active site, together with an arrangement of a water molecule positioned ~3.2 Å from the anomeric carbon of the substrate, supported a classic inverting mechanism, in which Asp265 activates the nucleophilic water and Glu268 protonates the leaving group. Substitution of these residues resulted in 200- to 15,000-fold reductions in activity, confirming their catalytic role.

== Three-dimensional structures ==
The three-dimensional structure of GH71 enzymes has been elucidated through two independent crystallographic studies, both revealing that members of this family adopt a classic (β/α)₈ TIM-barrel core, closely associated with a C-terminal β-sandwich accessory domain <cite>Horaguchi2025 Mazurkewich2025</cite>.

The first structural description, obtained for ''S. pombe'' Agn1p, showed that its TIM barrel forms a deep cavity accessible to the solvent, consistent with the catalytic cleft observed in other glycoside hydrolases. Structural work on ''A. nidulans'' AnGH71C corroborated this overall fold and showed that the β-sandwich closely resembles an Ig-like fibronectin III domain, compacting closely against the TIM barrel to form a long substrate-binding cleft comprising at least seven subsites (−4 to +3). The structures of ligand complexes revealed minimal protein rearrangement upon binding but highlighted a conformational packing of the β6–α6 loop over subsites +1 to +3, contributing to substrate stabilization.

Simulations and geometries of the bound state further indicated that GH71 enzymes exploit the intrinsic low-energy conformations of α-1,3-linked oligosaccharides, while a high-energy configuration around the −1/+1 region likely prepares the glycosidic bond for cleavage.

== Family Firsts ==
;First stereochemistry determination: The stereochemistry of GH71 enzymes has been resolved by monitoring the anomeric configuration of the released glucose using ¹H NMR spectroscopy, confirming that the enzymes operate through the inversion mechanism <cite>Grun2006</cite>.
;First general acid/base residue identification: In AnGH71C, the catalytic residues have been identified as a dyad, with an aspartate residue (Asp265) acting as a general base that activates the catalytic water molecule, and a glutamate residue (Glu268) acting as a general acid that protonates the leaving group <cite>Mazurkewich2025</cite>.
;First 3-D structure: The first solved structure of a GH71 enzyme was of Agn1p from ''S. pombe'', published in June 2025 by Horaguchi et al. <cite>Horaguchi2025</cite>, which demonstrated that members of the GH71 family possess a classic (β/α)₈ TIM-barrel core closely associated with a C-terminal β-sandwich accessory domain. In August the same year, Mazurkewich et al. published the structure of AnGH71C from ''A. nidulans'', which additionally included structures with glucose and nigerooligosaccharides bound in the active site, respectively <cite>Mazurkewich2025</cite>.

== References ==
<biblio>
#Zonneveld1972 pmid=4622000

#Imai1977 Imai K, Kobayashi M, Matsuda K. (1977). ''Properties of an α-1,3-glucanase from Streptomyces sp. KI-8''. ''Agric Biol Chem''. 1977;'''41'''(10);1889-95. [https://doi.org/10.1080/00021369.1977.10862782 DOI: 10.1080/00021369.1977.10862782]

#Fuglsang2000 pmid=10636904

#VillalobosDuno2013 pmid=23825576
#AitLahsen2001 pmid=11722942

#Dekker2004 pmid=15194814

#Mazurkewich2025 pmid=40877455

#Grun2006 pmid=16780840

#Sinitsyna2025 pmid=39846749

#Horaguchi2025 pmid=40306164
</biblio>


[[Category:Glycoside Hydrolase Families|GH071]]

Glycoside Hydrolase Family 71

2026-01-23T08:28:41Z

Johan Larsbrink:

{{UnderConstruction}}
* [[Author]]: [[User:Antonielle Vieira Monclaro|Antonielle Vieira Monclaro]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH71'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|inverting
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH71.html
|}
</div>

[[File: AnGH71C.png|thumb|right|500px|'''Figure 1. Structure of ''An''GH71C from ''Aspergillus nidulans''.''' The structure solved with nigerooligosaccharides as ligand is shown (PDB ID [{{PDBlink}}9fnh 9FNH]), with one protein molecule and oligosaccharides from different chains that together span the active site, as blue sticks. The core catalytic (α/β)8 barrel is shown in silver, the C-terminal β-sheet domain in pale orange, and the catalytic residues in green.]]

== Substrate specificities ==

GH71 comprises enzymes with α-1,3-glucanase activity (EC 3.2.1.59), often referred to as mutanases, based on mutan being an alternative name for α-1,3-glucan (from ''Streptococcus mutans''). Early studies demonstrated that these enzymes hydrolyze pure α-1,3-glucans while remaining inactive toward α-glucans containing mixed α-1,3/α-1,4 linkages <cite>Zonneveld1972</cite>. Subsequent work showed that GH71 enzymes act on a broader range of α-1,3-linked glucans, including pseudonigeran and soluble carboxymethylated α-1,3-glucan, but display no activity toward other tested α- or β-linked glycans <cite>Imai1977 Fuglsang2000 VillalobosDuno2013 AitLahsen2001 Dekker2004 Mazurkewich2025</cite>.

Depending on the enzyme, GH71 α-1,3-glucanases may exhibit exo- or endo-type hydrolytic activity. Some enzymes with exo activity, such as Agn13.1 from ''Trichoderma harzianum'', showed a 1:1 correlation between glucose released and reducing sugars, typical of exo hydrolysis, and was unable to cleave periodate-oxidized S-glucan, which is resistant to exo-α-1,3-glucanases <cite>AitLahsen2001</cite>. Endo-acting GH71 enzymes include Agn1p from ''Schizosaccharomyces pombe'' which does not hydrolyze pNP-α-glucose, and is not inhibited by classical exo-glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, or D-glucono-1,5-lactone <cite>Dekker2004</cite>. MutAp from ''T. harzianum'', an endo-hydrolytic α-1,3-glucanase, is suggested to act processively from the non-reducing end, repeatedly releasing glucose before dissociating <cite>Grun2006 Sinitsyna2025</cite>. Its insensitivity to multiple exo-glycosidase inhibitors, and experiments with reduced oligosaccharides (e.g., G5-ol) further yield no products compatible with exo activity (e.g., G4-ol). The minimum chain-length requirement for MutAp has been shown to be a tetrasaccharide.

The ''Aspergillus nidulans'' enzymes AnGH71B and AnGH71C display distinct behaviors when acting on reduced oligosaccharides (nigeropentaose and nigerohexaose), reflecting different cleavage mechanisms <cite>Mazurkewich2025</cite>. AnGH71C exhibits a pattern consistent with endo-cleavage, evidenced by the diverse products generated from reduced nigerohexaose. In contrast, AnGH71B displays exo-processive characteristics despite the absence of released reduced glucose, explained by the inability of subsite +1 to accommodate the reduced unit and therefore preventing classical terminal cleavage.

Overall, GH71 enzymes exhibit strict specificity for continuous regions of α-1,3-glycosidic linkages, with no tolerance for alternating segments containing α-1,4 linkages <cite>Zonneveld1972 AitLahsen2001</cite>, as found in the polysaccharide nigeran (α-1,3/1,4-glucan). End products range from glucose (e.g. from endo-acting processive action), to nigerooligosaccharides with DP 2–7 <cite>VillalobosDuno2013 Dekker2004 Sinitsyna2025</cite>. Nigerotriose has been found as a final product together with glucose from endo-acting processive GH71 enzymes <cite>Mazurkewich2025 Grun2006</cite>.

== Kinetics and Mechanism ==
The anomeric configuration of the products released by α-1,3-glucanases has been elucidated by complementary NMR and crystallography approaches. In the case of MutAp from ''T. harzianum'', the hydrolysis of carboxymethylated α-1,3-glucan was monitored by ¹H NMR, revealing the appearance of β-Glc signals and the complete absence of α-Glc, demonstrating inversion of the anomeric configuration <cite>Grun2006</cite>. NMR studies of AnGH71B and AnGH71C from ''A. nidulans'' likewise showed inversion of products, and structures including the inverted anomer of the product nigerose further supports these findings <cite>Mazurkewich2025</cite>.

== Catalytic Residues ==
Three conserved acidic residues (Asp69, Asp237, and Glu240) were identified in the active site of Agn1p by Horaguchi et al. <cite>Horaguchi2025</cite>. Individual substitutions of these residues (D69N, D237A/N, E240A/Q) led to drastic reductions in activity on α-1,3-glucan.

Structure-guided mutational studies of AnGH71B and AnGH71C directly identified the catalytic residues Asp265 (general base) and Glu268 (general acid), functionally separating subsites −4 to +3 of the enzymes <cite>Mazurkewich2025</cite>. The simultaneous observation of the α-linked substrate nigerotetraose and β-anomer of nigerotriose as product in the active site, together with an arrangement of a water molecule positioned ~3.2 Å from the anomeric carbon of the substrate, supported a classic inverting mechanism, in which Asp265 activates the nucleophilic water and Glu268 protonates the leaving group. Substitution of these residues resulted in 200- to 15,000-fold reductions in activity, confirming their catalytic role.

== Three-dimensional structures ==
The three-dimensional structure of GH71 enzymes has been elucidated through two independent crystallographic studies, both revealing that members of this family adopt a classic (β/α)₈ TIM-barrel core, closely associated with a C-terminal β-sandwich accessory domain <cite>Horaguchi2025 Mazurkewich2025</cite>.

The first structural description, obtained for ''S. pombe'' Agn1p, showed that its TIM barrel forms a deep cavity accessible to the solvent, consistent with the catalytic cleft observed in other glycoside hydrolases. Structural work on ''A. nidulans'' AnGH71C corroborated this overall fold and showed that the β-sandwich closely resembles an Ig-like fibronectin III domain, compacting closely against the TIM barrel to form a long substrate-binding cleft comprising at least seven subsites (−4 to +3). The structures of ligand complexes revealed minimal protein rearrangement upon binding but highlighted a conformational packing of the β6–α6 loop over subsites +1 to +3, contributing to substrate stabilization.

Simulations and geometries of the bound state further indicated that GH71 enzymes exploit the intrinsic low-energy conformations of α-1,3-linked oligosaccharides, while a high-energy configuration around the −1/+1 region likely prepares the glycosidic bond for cleavage.

== Family Firsts ==
;First stereochemistry determination: The stereochemistry of GH71 enzymes has been resolved by monitoring the anomeric configuration of the released glucose using ¹H NMR spectroscopy, confirming that the enzymes operate through the inversion mechanism <cite>Grun2006</cite>.
;First general acid/base residue identification: In AnGH71C, the catalytic residues have been identified as a dyad, with an aspartate residue (Asp265) acting as a general base that activates the catalytic water molecule, and a glutamate residue (Glu268) acting as a general acid that protonates the leaving group <cite>Mazurkewich2025</cite>.
;First 3-D structure: The first solved structure of a GH71 enzyme was of Agn1p from ''S. pombe'', published in June 2025 by Horaguchi et al. <cite>Horaguchi2025</cite>, which demonstrated that members of the GH71 family possess a classic (β/α)₈ TIM-barrel core closely associated with a C-terminal β-sandwich accessory domain. In August the same year, Mazurkewich et al. published the structure of AnGH71C from ''A. nidulans'', which additionally included structures with glucose and nigerooligosaccharides bound in the active site, respectively <cite>Mazurkewich2025</cite>.

== References ==
<biblio>
#Zonneveld1972 pmid=4622000

#Imai1977 Imai K, Kobayashi M, Matsuda K. (1977). ''Properties of an α-1,3-glucanase from Streptomyces sp. KI-8''. ''Agric Biol Chem''. 1977;'''41'''(10);1889-95. [https://doi.org/10.1080/00021369.1977.10862782 DOI: 10.1080/00021369.1977.10862782]

#Fuglsang2000 pmid=10636904

#VillalobosDuno2013 pmid=23825576
#AitLahsen2001 pmid=11722942

#Dekker2004 pmid=15194814

#Mazurkewich2025 pmid=40877455

#Grun2006 pmid=16780840

#Sinitsyna2025 pmid=39846749

#Horaguchi2025 pmid=40306164
</biblio>


[[Category:Glycoside Hydrolase Families|GH071]]

Glycoside Hydrolase Family 71

2026-01-22T10:37:16Z

Johan Larsbrink:

{{UnderConstruction}}
* [[Author]]: [[User:Antonielle Vieira Monclaro|Antonielle Vieira Monclaro]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH71'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|inverting
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH71.html
|}
</div>

[[File: AnGH71C.png|thumb|right|500px|'''Figure 1. Structure of ''An''GH71C from ''Aspergillus nidulans''.''' The structure solved with nigerooligosaccharides as ligand is shown (PDB ID [{{PDBlink}}9fnh 9FNH]), with one protein molecule and oligosaccharides from different chains that together span the active site, as blue sticks. The core catalytic (α/β)8 barrel is shown in silver, the C-terminal β-sheet domain in pale orange, and the catalytic residues in green.]]

== Substrate specificities ==

GH71 comprises enzymes with α-1,3-glucanase activity (EC 3.2.1.59), often referred to as mutanases, based on mutan being an alternative name for α-1,3-glucan ((from ''Streptococcus mutans''). Early studies demonstrated that these enzymes hydrolyze pure α-1,3-glucans while remaining inactive toward α-glucans containing mixed α-1,3/α-1,4 linkages <cite>Zonneveld1972</cite>. Subsequent work showed that GH71 enzymes act on a broader range of α-1,3-linked glucans, including pseudonigeran and soluble carboxymethylated α-1,3-glucan, but display no activity toward other tested α- or β-linked glycans <cite>Imai1977 Fuglsang2000 VillalobosDuno2013 AitLahsen2001 Dekker2004 Mazurkewich2025</cite>.

Depending on the enzyme, GH71 α-1,3-glucanases may exhibit exo- or endo-type hydrolytic activity. Some enzymes with exo activity, such as Agn13.1 from ''Trichoderma harzianum'', showed a 1:1 correlation between glucose released and reducing sugars, typical of exo hydrolysis, and was unable to cleave periodate-oxidized S-glucan, which is resistant to exo-α-1,3-glucanases <cite>AitLahsen2001</cite>. Endo-acting GH71 enzymes include Agn1p from ''Schizosaccharomyces pombe'' which does not hydrolyze pNP-α-glucose, and is not inhibited by classical exo-glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, or D-glucono-1,5-lactone <cite>Dekker2004</cite>. MutAp from ''Trichoderma harzianum'', an endo-hydrolytic α-1,3-glucanase, is suggested to act processively from the non-reducing end, repeatedly releasing glucose before dissociating <cite>Grun2006 Sinitsyna2025</cite>. Its insensitivity to multiple exo-glycosidase inhibitors, and experiments with reduced oligosaccharides (e.g., G5-ol) further yield no products compatible with exo activity (e.g., G4-ol). The minimum chain-length requirement for MutAp has been shown to be a tetrasaccharide.

The ''Aspergillus nidulans'' enzymes AnGH71B and AnGH71C display distinct behaviors when acting on reduced oligosaccharides (nigeropentaose and nigerohexaose), reflecting different cleavage mechanisms <cite>Mazurkewich2025</cite>. AnGH71C exhibits a pattern consistent with endo-cleavage, evidenced by the diverse products generated from reduced nigerohexaose. In contrast, AnGH71B displays exo-processive characteristics despite the absence of released reduced glucose, explained by the inability of subsite +1 to accommodate the reduced unit and therefore preventing classical terminal cleavage.

Overall, GH71 enzymes exhibit strict specificity for continuous regions of α-1,3-glycosidic linkages, with no tolerance for alternating segments containing α-1,4 linkages <cite>Zonneveld1972 AitLahsen2001</cite>, as found in the polysaccharide nigeran (α-1,3/1,4-glucan). End products range from glucose (e.g. from endo-acting processive action), to nigerooligosaccharides with DP 2–7 <cite>VillalobosDuno2013 Dekker2004 Sinitsyna2025</cite>. Nigerotriose has been found as a final product together with glucose from endo-acting processive GH71 enzymes <cite>Mazurkewich2025 Grun2006</cite>.

== Kinetics and Mechanism ==
The anomeric configuration of the products released by α-1,3-glucanases has been elucidated by complementary NMR and crystallography approaches. In the case of MutAp from ''Trichoderma harzianum'', the hydrolysis of carboxymethylated α-1,3-glucan was monitored by ¹H NMR, revealing the appearance of β-Glc signals and the complete absence of α-Glc, demonstrating inversion of the anomeric configuration <cite>Grun2006</cite>. NMR studies of AnGH71B and AnGH71C from ''Aspergillus nidulans'' likewise showed inversion of products, and structures including the inverted product nigerose further supports these findings <cite>Mazurkewich2025</cite>

== Catalytic Residues ==
Three conserved acidic residues (Asp69, Asp237, and Glu240) were identified in the active site of Agn1p by Horaguchi et al. <cite>Horaguchi2025</cite>. Individual substitutions of these residues (D69N, D237A/N, E240A/Q) led to drastic reductions in activity on α-1,3-glucan.

Structure-guided mutational studies of AnGH71B and AnGH71C directly identified the catalytic residues Asp265 (general base) and Glu268 (general acid), functionally separating subsites −4 to +3 of the enzymes <cite>Mazurkewich2025</cite>. The simultaneous observation of the α-linked substrate nigerotetraose and β-anomer of nigerotriose as product in the active site, together with an arrangement of a water molecule positioned ~3.2 Å from the anomeric carbon of the substrate, supported a classic inverting mechanism, in which Asp265 activates the nucleophilic water and Glu268 protonates the leaving group. Substitution of these residues resulted in 200- to 15,000-fold reductions in activity, confirming their catalytic role.

== Three-dimensional structures ==
The three-dimensional structure of GH71 enzymes has been elucidated through two independent crystallographic studies, both revealing that members of this family adopt a classic (β/α)₈ TIM-barrel core, closely associated with a C-terminal β-sandwich accessory domain <cite>Horaguchi2025 Mazurkewich2025</cite>.

The first structural description, obtained for ''Schizosaccharomyces pombe'' Agn1p, showed that its TIM barrel forms a deep cavity accessible to the solvent, consistent with the catalytic cleft observed in other glycoside hydrolases. Structural work on ''Aspergillus niger'' AnGH71C corroborated this overall fold and showed that the β-sandwich closely resembles an Ig-like fibronectin III domain, compacting closely against the TIM barrel to form a long substrate-binding cleft comprising at least seven subsites (−4 to +3). The structures of ligand complexes revealed minimal protein rearrangement upon binding but highlighted a conformational packing of the β6–α6 loop over subsites +1 to +3, contributing to substrate stabilization.

Simulations and geometries of the bound state further indicated that GH71 enzymes exploit the intrinsic low-energy conformations of α-1,3-linked oligosaccharides, while a high-energy configuration around the −1/+1 region likely prepares the glycosidic bond for cleavage.

== Family Firsts ==
;First stereochemistry determination: The stereochemistry of GH71 enzymes has been resolved by monitoring the anomeric configuration of the released glucose using ¹H NMR spectroscopy, confirming that the enzymes operate through the inversion mechanism <cite>Grun2006</cite>.
;First catalytic nucleophile identification: Content is to be added here.
;First general acid/base residue identification: In AnGH71C, the catalytic residues have been identified as a dyad, with an aspartate residue (Asp265) acting as a general base that activates the catalytic water molecule, and a glutamate residue (Glu268) acting as a general acid that protonates the leaving group <cite>Mazurkewich2025</cite>.
;First 3-D structure: The first solved structure of a GH71 enzyme was of Agn1p from ''Schizosaccharomyces pombe'', published in June 2025 by Horaguchi et al. <cite>Horaguchi2025</cite>, which demonstrated that members of the GH71 family possess a classic (β/α)₈ TIM-barrel core closely associated with a C-terminal β-sandwich accessory domain. In August the same year, Mazurkewich et al. published the structure of AnGH71C from ''Aspergillus nidulans'', which additionally included structures with glucose and nigerotetraose bound in the active site, respectively <cite>Mazurkewich2025</cite>.

== References ==
<biblio>
#Zonneveld1972 pmid=4622000

#Imai1977 Imai, K., Kobayashi, M. and Matsuda, K. (1977) ‘Properties of an α-1,3-glucanase from Streptomyces sp. KI-8’, Agricultural and Biological Chemistry, 41, pp. 1889–1895. [https://doi.org/10.1080/00021369.1977.10862782 DOI: 10.1080/00021369.1977.10862782]

#Fuglsang2000 Fuglsang, C.C., Berka, R.M., Wahleithner, J.A., Kauppinen, S., Shuster, J.R., Rasmussen, G., Halkier, T., Dalbøge, H. and Henrissat, B. (2000) ‘Biochemical analysis of recombinant fungal mutanases’, Journal of Biological Chemistry, 275, pp. 2009–2018. [https://doi.org/10.1074/jbc.275.3.2009 DOI: 10.1074/jbc.275.3.2009]

#VillalobosDuno2013 Villalobos-Duno, H., San-Blas, G., Paulinkevicius, M., Sánchez-Martín, Y. and Nino-Vega, G. (2013) ‘Biochemical characterization of Paracoccidioides brasiliensis α-1,3-glucanase Agn1p, and its functionality by heterologous expression in Schizosaccharomyces pombe’, PLoS ONE, 8, e66853. [https://doi.org/10.1371/journal.pone.0066853 DOI: 10.1371/journal.pone.0066853]

#AitLahsen2001 Ait-Lahsen, H., Soler, A., Rey, M., De La Cruz, J., Monte, E. and Llobell, A. (2001) ‘An antifungal exo-α-1,3-glucanase (AGN13.1) from the biocontrol fungus Trichoderma harzianum’, Applied and Environmental Microbiology, 67, pp. 5833–5839. [https://doi.org/10.1128/AEM.67.12.5833-5839.2001 DOI: 10.1128/AEM.67.12.5833-5839.2001]

#Dekker2004 Dekker, N., Speijer, D., Grün, C.H., Van den Berg, M., De Haan, A. and Hochstenbach, F. (2004) ‘Role of the α-glucanase Agn1p in fission-yeast cell separation’, Molecular Biology of the Cell, 15, pp. 3903–3914. [https://doi.org/10.1091/mbc.E04 DOI: 10.1091/mbc.E04]

#Mazurkewich2025 Mazurkewich, S., Widén, T., Karlsson, H., Evenäs, L., Ramamohan, P., Wohlert, J., Brändén, G. and Larsbrink, J. (2025) ‘Structural and biochemical basis for activity of Aspergillus nidulans α-1,3-glucanases from glycoside hydrolase family 71’, Communications Biology, 8. [https://doi.org/10.1038/s42003-025-08696-3 DOI: 10.1038/s42003-025-08696-3]

#Grun2006 Grün, C.H., Dekker, N., Nieuwland, A.A., Klis, F.M., Kamerling, J.P., Vliegenthart, J.F.G. and Hochstenbach, F. (2006) ‘Mechanism of action of the endo-(1→3)-α-glucanase MutAp from the mycoparasitic fungus Trichoderma harzianum’, FEBS Letters, 580, pp. 3780–3786. [https://doi.org/10.1016/j.febslet.2006.05.062 DOI: 10.1016/j.febslet.2006.05.062]

#Sinitsyna2025 Sinitsyna, O.A., Volkov, P.V., Zorov, I.N., Rozhkova, A.M., Emshanov, O.V., Romanova, Y.M., Komarova, B.S., Novikova, N.S., Nifantiev, N.E. and Sinitsyn, A.P. (2025) ‘Physico-chemical properties and substrate specificity of α-(1→3)-D-glucan degrading recombinant mutanase from Trichoderma harzianum expressed in Penicillium verruculosum’, Applied and Environmental Microbiology, 91. [https://doi.org/10.1128/aem.00226-24 DOI: 10.1128/aem.00226-24]

#Horaguchi2025 Horaguchi, Y., Saitoh, H., Konno, H., Makabe, K. and Yano, S. (2025) ‘Crystal structure of GH71 α-1,3-glucanase Agn1p from Schizosaccharomyces pombe: an enzyme regulating cell division in fission yeast’, Biochemical and Biophysical Research Communications, 766. [https://doi.org/10.1016/j.bbrc.2025.151907 DOI: 10.1016/j.bbrc.2025.151907]
</biblio>


[[Category:Glycoside Hydrolase Families|GH071]]

Glycoside Hydrolase Family 71

2026-01-22T10:36:41Z

Johan Larsbrink:

{{UnderConstruction}}
* [[Author]]: [[User:Antonielle Vieira Monclaro|Antonielle Vieira Monclaro]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH71'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|inverting
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH71.html
|}
</div>

[[File: AnGH71C.png|thumb|right|500px|'''Figure 1. Structure of ''An''GH71C from ''Aspergillus nidulans''.''' The structure solved with nigerooligosaccharides as ligand is shown (PDB ID [{{PDBlink}}9fnh 9FNH]), with one protein molecule and oligosaccharides from different chains that together span the active site, as blue sticks. The core catalytic (α/β)8 barrel is shown in silver and the C-terminal β-sheet domain in pale orange.]]

== Substrate specificities ==

GH71 comprises enzymes with α-1,3-glucanase activity (EC 3.2.1.59), often referred to as mutanases, based on mutan being an alternative name for α-1,3-glucan ((from ''Streptococcus mutans''). Early studies demonstrated that these enzymes hydrolyze pure α-1,3-glucans while remaining inactive toward α-glucans containing mixed α-1,3/α-1,4 linkages <cite>Zonneveld1972</cite>. Subsequent work showed that GH71 enzymes act on a broader range of α-1,3-linked glucans, including pseudonigeran and soluble carboxymethylated α-1,3-glucan, but display no activity toward other tested α- or β-linked glycans <cite>Imai1977 Fuglsang2000 VillalobosDuno2013 AitLahsen2001 Dekker2004 Mazurkewich2025</cite>.

Depending on the enzyme, GH71 α-1,3-glucanases may exhibit exo- or endo-type hydrolytic activity. Some enzymes with exo activity, such as Agn13.1 from ''Trichoderma harzianum'', showed a 1:1 correlation between glucose released and reducing sugars, typical of exo hydrolysis, and was unable to cleave periodate-oxidized S-glucan, which is resistant to exo-α-1,3-glucanases <cite>AitLahsen2001</cite>. Endo-acting GH71 enzymes include Agn1p from ''Schizosaccharomyces pombe'' which does not hydrolyze pNP-α-glucose, and is not inhibited by classical exo-glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, or D-glucono-1,5-lactone <cite>Dekker2004</cite>. MutAp from ''Trichoderma harzianum'', an endo-hydrolytic α-1,3-glucanase, is suggested to act processively from the non-reducing end, repeatedly releasing glucose before dissociating <cite>Grun2006 Sinitsyna2025</cite>. Its insensitivity to multiple exo-glycosidase inhibitors, and experiments with reduced oligosaccharides (e.g., G5-ol) further yield no products compatible with exo activity (e.g., G4-ol). The minimum chain-length requirement for MutAp has been shown to be a tetrasaccharide.

The ''Aspergillus nidulans'' enzymes AnGH71B and AnGH71C display distinct behaviors when acting on reduced oligosaccharides (nigeropentaose and nigerohexaose), reflecting different cleavage mechanisms <cite>Mazurkewich2025</cite>. AnGH71C exhibits a pattern consistent with endo-cleavage, evidenced by the diverse products generated from reduced nigerohexaose. In contrast, AnGH71B displays exo-processive characteristics despite the absence of released reduced glucose, explained by the inability of subsite +1 to accommodate the reduced unit and therefore preventing classical terminal cleavage.

Overall, GH71 enzymes exhibit strict specificity for continuous regions of α-1,3-glycosidic linkages, with no tolerance for alternating segments containing α-1,4 linkages <cite>Zonneveld1972 AitLahsen2001</cite>, as found in the polysaccharide nigeran (α-1,3/1,4-glucan). End products range from glucose (e.g. from endo-acting processive action), to nigerooligosaccharides with DP 2–7 <cite>VillalobosDuno2013 Dekker2004 Sinitsyna2025</cite>. Nigerotriose has been found as a final product together with glucose from endo-acting processive GH71 enzymes <cite>Mazurkewich2025 Grun2006</cite>.

== Kinetics and Mechanism ==
The anomeric configuration of the products released by α-1,3-glucanases has been elucidated by complementary NMR and crystallography approaches. In the case of MutAp from ''Trichoderma harzianum'', the hydrolysis of carboxymethylated α-1,3-glucan was monitored by ¹H NMR, revealing the appearance of β-Glc signals and the complete absence of α-Glc, demonstrating inversion of the anomeric configuration <cite>Grun2006</cite>. NMR studies of AnGH71B and AnGH71C from ''Aspergillus nidulans'' likewise showed inversion of products, and structures including the inverted product nigerose further supports these findings <cite>Mazurkewich2025</cite>

== Catalytic Residues ==
Three conserved acidic residues (Asp69, Asp237, and Glu240) were identified in the active site of Agn1p by Horaguchi et al. <cite>Horaguchi2025</cite>. Individual substitutions of these residues (D69N, D237A/N, E240A/Q) led to drastic reductions in activity on α-1,3-glucan.

Structure-guided mutational studies of AnGH71B and AnGH71C directly identified the catalytic residues Asp265 (general base) and Glu268 (general acid), functionally separating subsites −4 to +3 of the enzymes <cite>Mazurkewich2025</cite>. The simultaneous observation of the α-linked substrate nigerotetraose and β-anomer of nigerotriose as product in the active site, together with an arrangement of a water molecule positioned ~3.2 Å from the anomeric carbon of the substrate, supported a classic inverting mechanism, in which Asp265 activates the nucleophilic water and Glu268 protonates the leaving group. Substitution of these residues resulted in 200- to 15,000-fold reductions in activity, confirming their catalytic role.

== Three-dimensional structures ==
The three-dimensional structure of GH71 enzymes has been elucidated through two independent crystallographic studies, both revealing that members of this family adopt a classic (β/α)₈ TIM-barrel core, closely associated with a C-terminal β-sandwich accessory domain <cite>Horaguchi2025 Mazurkewich2025</cite>.

The first structural description, obtained for ''Schizosaccharomyces pombe'' Agn1p, showed that its TIM barrel forms a deep cavity accessible to the solvent, consistent with the catalytic cleft observed in other glycoside hydrolases. Structural work on ''Aspergillus niger'' AnGH71C corroborated this overall fold and showed that the β-sandwich closely resembles an Ig-like fibronectin III domain, compacting closely against the TIM barrel to form a long substrate-binding cleft comprising at least seven subsites (−4 to +3). The structures of ligand complexes revealed minimal protein rearrangement upon binding but highlighted a conformational packing of the β6–α6 loop over subsites +1 to +3, contributing to substrate stabilization.

Simulations and geometries of the bound state further indicated that GH71 enzymes exploit the intrinsic low-energy conformations of α-1,3-linked oligosaccharides, while a high-energy configuration around the −1/+1 region likely prepares the glycosidic bond for cleavage.

== Family Firsts ==
;First stereochemistry determination: The stereochemistry of GH71 enzymes has been resolved by monitoring the anomeric configuration of the released glucose using ¹H NMR spectroscopy, confirming that the enzymes operate through the inversion mechanism <cite>Grun2006</cite>.
;First catalytic nucleophile identification: Content is to be added here.
;First general acid/base residue identification: In AnGH71C, the catalytic residues have been identified as a dyad, with an aspartate residue (Asp265) acting as a general base that activates the catalytic water molecule, and a glutamate residue (Glu268) acting as a general acid that protonates the leaving group <cite>Mazurkewich2025</cite>.
;First 3-D structure: The first solved structure of a GH71 enzyme was of Agn1p from ''Schizosaccharomyces pombe'', published in June 2025 by Horaguchi et al. <cite>Horaguchi2025</cite>, which demonstrated that members of the GH71 family possess a classic (β/α)₈ TIM-barrel core closely associated with a C-terminal β-sandwich accessory domain. In August the same year, Mazurkewich et al. published the structure of AnGH71C from ''Aspergillus nidulans'', which additionally included structures with glucose and nigerotetraose bound in the active site, respectively <cite>Mazurkewich2025</cite>.

== References ==
<biblio>
#Zonneveld1972 pmid=4622000

#Imai1977 Imai, K., Kobayashi, M. and Matsuda, K. (1977) ‘Properties of an α-1,3-glucanase from Streptomyces sp. KI-8’, Agricultural and Biological Chemistry, 41, pp. 1889–1895. [https://doi.org/10.1080/00021369.1977.10862782 DOI: 10.1080/00021369.1977.10862782]

#Fuglsang2000 Fuglsang, C.C., Berka, R.M., Wahleithner, J.A., Kauppinen, S., Shuster, J.R., Rasmussen, G., Halkier, T., Dalbøge, H. and Henrissat, B. (2000) ‘Biochemical analysis of recombinant fungal mutanases’, Journal of Biological Chemistry, 275, pp. 2009–2018. [https://doi.org/10.1074/jbc.275.3.2009 DOI: 10.1074/jbc.275.3.2009]

#VillalobosDuno2013 Villalobos-Duno, H., San-Blas, G., Paulinkevicius, M., Sánchez-Martín, Y. and Nino-Vega, G. (2013) ‘Biochemical characterization of Paracoccidioides brasiliensis α-1,3-glucanase Agn1p, and its functionality by heterologous expression in Schizosaccharomyces pombe’, PLoS ONE, 8, e66853. [https://doi.org/10.1371/journal.pone.0066853 DOI: 10.1371/journal.pone.0066853]

#AitLahsen2001 Ait-Lahsen, H., Soler, A., Rey, M., De La Cruz, J., Monte, E. and Llobell, A. (2001) ‘An antifungal exo-α-1,3-glucanase (AGN13.1) from the biocontrol fungus Trichoderma harzianum’, Applied and Environmental Microbiology, 67, pp. 5833–5839. [https://doi.org/10.1128/AEM.67.12.5833-5839.2001 DOI: 10.1128/AEM.67.12.5833-5839.2001]

#Dekker2004 Dekker, N., Speijer, D., Grün, C.H., Van den Berg, M., De Haan, A. and Hochstenbach, F. (2004) ‘Role of the α-glucanase Agn1p in fission-yeast cell separation’, Molecular Biology of the Cell, 15, pp. 3903–3914. [https://doi.org/10.1091/mbc.E04 DOI: 10.1091/mbc.E04]

#Mazurkewich2025 Mazurkewich, S., Widén, T., Karlsson, H., Evenäs, L., Ramamohan, P., Wohlert, J., Brändén, G. and Larsbrink, J. (2025) ‘Structural and biochemical basis for activity of Aspergillus nidulans α-1,3-glucanases from glycoside hydrolase family 71’, Communications Biology, 8. [https://doi.org/10.1038/s42003-025-08696-3 DOI: 10.1038/s42003-025-08696-3]

#Grun2006 Grün, C.H., Dekker, N., Nieuwland, A.A., Klis, F.M., Kamerling, J.P., Vliegenthart, J.F.G. and Hochstenbach, F. (2006) ‘Mechanism of action of the endo-(1→3)-α-glucanase MutAp from the mycoparasitic fungus Trichoderma harzianum’, FEBS Letters, 580, pp. 3780–3786. [https://doi.org/10.1016/j.febslet.2006.05.062 DOI: 10.1016/j.febslet.2006.05.062]

#Sinitsyna2025 Sinitsyna, O.A., Volkov, P.V., Zorov, I.N., Rozhkova, A.M., Emshanov, O.V., Romanova, Y.M., Komarova, B.S., Novikova, N.S., Nifantiev, N.E. and Sinitsyn, A.P. (2025) ‘Physico-chemical properties and substrate specificity of α-(1→3)-D-glucan degrading recombinant mutanase from Trichoderma harzianum expressed in Penicillium verruculosum’, Applied and Environmental Microbiology, 91. [https://doi.org/10.1128/aem.00226-24 DOI: 10.1128/aem.00226-24]

#Horaguchi2025 Horaguchi, Y., Saitoh, H., Konno, H., Makabe, K. and Yano, S. (2025) ‘Crystal structure of GH71 α-1,3-glucanase Agn1p from Schizosaccharomyces pombe: an enzyme regulating cell division in fission yeast’, Biochemical and Biophysical Research Communications, 766. [https://doi.org/10.1016/j.bbrc.2025.151907 DOI: 10.1016/j.bbrc.2025.151907]
</biblio>


[[Category:Glycoside Hydrolase Families|GH071]]

Glycoside Hydrolase Family 71

2026-01-22T10:36:03Z

Johan Larsbrink:

{{UnderConstruction}}
* [[Author]]: [[User:Antonielle Vieira Monclaro|Antonielle Vieira Monclaro]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH71'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|inverting
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH71.html
|}
</div>

[[File: AnGH71C.png|thumb|right|500px|'''Figure 1. Structure of AnGH71C from ''Aspergillus nidulans''.''' The structure solved with nigerooligosaccharides as ligand is shown (PDB ID [{{PDBlink}}9fnh 9FNH]), with one protein molecule and oligosaccharides from different chains that together span the active site. The core catalytic (α/β)8 barrel is shown in silver and the C-terminal β-sheet domain in pale orange.]]

== Substrate specificities ==

GH71 comprises enzymes with α-1,3-glucanase activity (EC 3.2.1.59), often referred to as mutanases, based on mutan being an alternative name for α-1,3-glucan ((from ''Streptococcus mutans''). Early studies demonstrated that these enzymes hydrolyze pure α-1,3-glucans while remaining inactive toward α-glucans containing mixed α-1,3/α-1,4 linkages <cite>Zonneveld1972</cite>. Subsequent work showed that GH71 enzymes act on a broader range of α-1,3-linked glucans, including pseudonigeran and soluble carboxymethylated α-1,3-glucan, but display no activity toward other tested α- or β-linked glycans <cite>Imai1977 Fuglsang2000 VillalobosDuno2013 AitLahsen2001 Dekker2004 Mazurkewich2025</cite>.

Depending on the enzyme, GH71 α-1,3-glucanases may exhibit exo- or endo-type hydrolytic activity. Some enzymes with exo activity, such as Agn13.1 from ''Trichoderma harzianum'', showed a 1:1 correlation between glucose released and reducing sugars, typical of exo hydrolysis, and was unable to cleave periodate-oxidized S-glucan, which is resistant to exo-α-1,3-glucanases <cite>AitLahsen2001</cite>. Endo-acting GH71 enzymes include Agn1p from ''Schizosaccharomyces pombe'' which does not hydrolyze pNP-α-glucose, and is not inhibited by classical exo-glycosidase inhibitors such as 1-deoxynojirimycin, castanospermine, or D-glucono-1,5-lactone <cite>Dekker2004</cite>. MutAp from ''Trichoderma harzianum'', an endo-hydrolytic α-1,3-glucanase, is suggested to act processively from the non-reducing end, repeatedly releasing glucose before dissociating <cite>Grun2006 Sinitsyna2025</cite>. Its insensitivity to multiple exo-glycosidase inhibitors, and experiments with reduced oligosaccharides (e.g., G5-ol) further yield no products compatible with exo activity (e.g., G4-ol). The minimum chain-length requirement for MutAp has been shown to be a tetrasaccharide.

The ''Aspergillus nidulans'' enzymes AnGH71B and AnGH71C display distinct behaviors when acting on reduced oligosaccharides (nigeropentaose and nigerohexaose), reflecting different cleavage mechanisms <cite>Mazurkewich2025</cite>. AnGH71C exhibits a pattern consistent with endo-cleavage, evidenced by the diverse products generated from reduced nigerohexaose. In contrast, AnGH71B displays exo-processive characteristics despite the absence of released reduced glucose, explained by the inability of subsite +1 to accommodate the reduced unit and therefore preventing classical terminal cleavage.

Overall, GH71 enzymes exhibit strict specificity for continuous regions of α-1,3-glycosidic linkages, with no tolerance for alternating segments containing α-1,4 linkages <cite>Zonneveld1972 AitLahsen2001</cite>, as found in the polysaccharide nigeran (α-1,3/1,4-glucan). End products range from glucose (e.g. from endo-acting processive action), to nigerooligosaccharides with DP 2–7 <cite>VillalobosDuno2013 Dekker2004 Sinitsyna2025</cite>. Nigerotriose has been found as a final product together with glucose from endo-acting processive GH71 enzymes <cite>Mazurkewich2025 Grun2006</cite>.

== Kinetics and Mechanism ==
The anomeric configuration of the products released by α-1,3-glucanases has been elucidated by complementary NMR and crystallography approaches. In the case of MutAp from ''Trichoderma harzianum'', the hydrolysis of carboxymethylated α-1,3-glucan was monitored by ¹H NMR, revealing the appearance of β-Glc signals and the complete absence of α-Glc, demonstrating inversion of the anomeric configuration <cite>Grun2006</cite>. NMR studies of AnGH71B and AnGH71C from ''Aspergillus nidulans'' likewise showed inversion of products, and structures including the inverted product nigerose further supports these findings <cite>Mazurkewich2025</cite>

== Catalytic Residues ==
Three conserved acidic residues (Asp69, Asp237, and Glu240) were identified in the active site of Agn1p by Horaguchi et al. <cite>Horaguchi2025</cite>. Individual substitutions of these residues (D69N, D237A/N, E240A/Q) led to drastic reductions in activity on α-1,3-glucan.

Structure-guided mutational studies of AnGH71B and AnGH71C directly identified the catalytic residues Asp265 (general base) and Glu268 (general acid), functionally separating subsites −4 to +3 of the enzymes <cite>Mazurkewich2025</cite>. The simultaneous observation of the α-linked substrate nigerotetraose and β-anomer of nigerotriose as product in the active site, together with an arrangement of a water molecule positioned ~3.2 Å from the anomeric carbon of the substrate, supported a classic inverting mechanism, in which Asp265 activates the nucleophilic water and Glu268 protonates the leaving group. Substitution of these residues resulted in 200- to 15,000-fold reductions in activity, confirming their catalytic role.

== Three-dimensional structures ==
The three-dimensional structure of GH71 enzymes has been elucidated through two independent crystallographic studies, both revealing that members of this family adopt a classic (β/α)₈ TIM-barrel core, closely associated with a C-terminal β-sandwich accessory domain <cite>Horaguchi2025 Mazurkewich2025</cite>.

The first structural description, obtained for ''Schizosaccharomyces pombe'' Agn1p, showed that its TIM barrel forms a deep cavity accessible to the solvent, consistent with the catalytic cleft observed in other glycoside hydrolases. Structural work on ''Aspergillus niger'' AnGH71C corroborated this overall fold and showed that the β-sandwich closely resembles an Ig-like fibronectin III domain, compacting closely against the TIM barrel to form a long substrate-binding cleft comprising at least seven subsites (−4 to +3). The structures of ligand complexes revealed minimal protein rearrangement upon binding but highlighted a conformational packing of the β6–α6 loop over subsites +1 to +3, contributing to substrate stabilization.

Simulations and geometries of the bound state further indicated that GH71 enzymes exploit the intrinsic low-energy conformations of α-1,3-linked oligosaccharides, while a high-energy configuration around the −1/+1 region likely prepares the glycosidic bond for cleavage.

== Family Firsts ==
;First stereochemistry determination: The stereochemistry of GH71 enzymes has been resolved by monitoring the anomeric configuration of the released glucose using ¹H NMR spectroscopy, confirming that the enzymes operate through the inversion mechanism <cite>Grun2006</cite>.
;First catalytic nucleophile identification: Content is to be added here.
;First general acid/base residue identification: In AnGH71C, the catalytic residues have been identified as a dyad, with an aspartate residue (Asp265) acting as a general base that activates the catalytic water molecule, and a glutamate residue (Glu268) acting as a general acid that protonates the leaving group <cite>Mazurkewich2025</cite>.
;First 3-D structure: The first solved structure of a GH71 enzyme was of Agn1p from ''Schizosaccharomyces pombe'', published in June 2025 by Horaguchi et al. <cite>Horaguchi2025</cite>, which demonstrated that members of the GH71 family possess a classic (β/α)₈ TIM-barrel core closely associated with a C-terminal β-sandwich accessory domain. In August the same year, Mazurkewich et al. published the structure of AnGH71C from ''Aspergillus nidulans'', which additionally included structures with glucose and nigerotetraose bound in the active site, respectively <cite>Mazurkewich2025</cite>.

== References ==
<biblio>
#Zonneveld1972 pmid=4622000

#Imai1977 Imai, K., Kobayashi, M. and Matsuda, K. (1977) ‘Properties of an α-1,3-glucanase from Streptomyces sp. KI-8’, Agricultural and Biological Chemistry, 41, pp. 1889–1895. [https://doi.org/10.1080/00021369.1977.10862782 DOI: 10.1080/00021369.1977.10862782]

#Fuglsang2000 Fuglsang, C.C., Berka, R.M., Wahleithner, J.A., Kauppinen, S., Shuster, J.R., Rasmussen, G., Halkier, T., Dalbøge, H. and Henrissat, B. (2000) ‘Biochemical analysis of recombinant fungal mutanases’, Journal of Biological Chemistry, 275, pp. 2009–2018. [https://doi.org/10.1074/jbc.275.3.2009 DOI: 10.1074/jbc.275.3.2009]

#VillalobosDuno2013 Villalobos-Duno, H., San-Blas, G., Paulinkevicius, M., Sánchez-Martín, Y. and Nino-Vega, G. (2013) ‘Biochemical characterization of Paracoccidioides brasiliensis α-1,3-glucanase Agn1p, and its functionality by heterologous expression in Schizosaccharomyces pombe’, PLoS ONE, 8, e66853. [https://doi.org/10.1371/journal.pone.0066853 DOI: 10.1371/journal.pone.0066853]

#AitLahsen2001 Ait-Lahsen, H., Soler, A., Rey, M., De La Cruz, J., Monte, E. and Llobell, A. (2001) ‘An antifungal exo-α-1,3-glucanase (AGN13.1) from the biocontrol fungus Trichoderma harzianum’, Applied and Environmental Microbiology, 67, pp. 5833–5839. [https://doi.org/10.1128/AEM.67.12.5833-5839.2001 DOI: 10.1128/AEM.67.12.5833-5839.2001]

#Dekker2004 Dekker, N., Speijer, D., Grün, C.H., Van den Berg, M., De Haan, A. and Hochstenbach, F. (2004) ‘Role of the α-glucanase Agn1p in fission-yeast cell separation’, Molecular Biology of the Cell, 15, pp. 3903–3914. [https://doi.org/10.1091/mbc.E04 DOI: 10.1091/mbc.E04]

#Mazurkewich2025 Mazurkewich, S., Widén, T., Karlsson, H., Evenäs, L., Ramamohan, P., Wohlert, J., Brändén, G. and Larsbrink, J. (2025) ‘Structural and biochemical basis for activity of Aspergillus nidulans α-1,3-glucanases from glycoside hydrolase family 71’, Communications Biology, 8. [https://doi.org/10.1038/s42003-025-08696-3 DOI: 10.1038/s42003-025-08696-3]

#Grun2006 Grün, C.H., Dekker, N., Nieuwland, A.A., Klis, F.M., Kamerling, J.P., Vliegenthart, J.F.G. and Hochstenbach, F. (2006) ‘Mechanism of action of the endo-(1→3)-α-glucanase MutAp from the mycoparasitic fungus Trichoderma harzianum’, FEBS Letters, 580, pp. 3780–3786. [https://doi.org/10.1016/j.febslet.2006.05.062 DOI: 10.1016/j.febslet.2006.05.062]

#Sinitsyna2025 Sinitsyna, O.A., Volkov, P.V., Zorov, I.N., Rozhkova, A.M., Emshanov, O.V., Romanova, Y.M., Komarova, B.S., Novikova, N.S., Nifantiev, N.E. and Sinitsyn, A.P. (2025) ‘Physico-chemical properties and substrate specificity of α-(1→3)-D-glucan degrading recombinant mutanase from Trichoderma harzianum expressed in Penicillium verruculosum’, Applied and Environmental Microbiology, 91. [https://doi.org/10.1128/aem.00226-24 DOI: 10.1128/aem.00226-24]

#Horaguchi2025 Horaguchi, Y., Saitoh, H., Konno, H., Makabe, K. and Yano, S. (2025) ‘Crystal structure of GH71 α-1,3-glucanase Agn1p from Schizosaccharomyces pombe: an enzyme regulating cell division in fission yeast’, Biochemical and Biophysical Research Communications, 766. [https://doi.org/10.1016/j.bbrc.2025.151907 DOI: 10.1016/j.bbrc.2025.151907]
</biblio>


[[Category:Glycoside Hydrolase Families|GH071]]

File:AnGH71C.png

2026-01-22T10:02:23Z

Johan Larsbrink:

Structure of AnGH71C, with nigerooligosaccharide ligands.

Carbohydrate Binding Module Family 9

2023-08-31T11:37:52Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-31T11:36:57Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-31T11:35:54Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T16:20:23Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T15:24:22Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T15:18:41Z

Johan Larsbrink:

Carbohydrate Esterase Family 15

2023-08-16T15:15:17Z

Johan Larsbrink:

{{CuratorApproved}}
* [[Author]]: [[User:Jenny Arnling Bååth|Jenny Arnling Bååth]] and [[User:Scott Mazurkewich|Scott Mazurkewich]]
* [[Responsible Curator]]: [[User:Johan Larsbrink|Johan Larsbrink]]
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Carbohydrate Esterase Family CE15'''
|-
||'''Acid/alcohol sugar substrate'''
|Acid
|-
|'''Mechanism'''
|serine hydrolase
|-
|'''Active site residues'''
|known, catalytic triad
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}CE15.html
|}
</div>


[[File: CE15_CAZypedia_Figure.png|thumb|right|400px|'''Figure 1. Comparison of structurally determined CE15 members.''' The enzymes (A) ''St''GE2 from ''Thermothelomyces thermophila'' (PDB ID [{{PDBlink}}4g4j 4G4J]), (B) ''Ot''CE15A from ''Opitutus terrae'' (PDB ID [{{PDBlink}}6gs0 6GS0]), and (C) ''Tt''CE15A from ''Teredinibacter turnerae'' (PDB ID [{{PDBlink}}6hsw 6HSW]) are shown in cartoon representation. The catalytic triad in each enzyme is shown as sticks and the methyl ester of 4-''O''-methyl glucuronoate first observed in ''St''GE2 is shown in all structures as green sticks. While all CE15 members contain the alpha/beta hydrolase fold, the most prominent difference across the CE15 family observed to-date are the presence, absence, or variety of inserted regions that protrude and build-up ridges around the active site (the differently colored regions in the ''Ot''CE15A and ''Tt''CE15A). The extent to which these regions affect the enzyme’s substrate specificity has yet to be fully elucidated.]]

== Substrate specificity ==
All CE15 enzymes characterized to date are glucuronoyl esterases (EC number [https://iubmb.qmul.ac.uk/enzyme/EC3/1/1/117.html 3.1.1.117]), cleaving esters of D-glucuronic acid. The first reported glucuronoyl esterase was ''Sc''GE1 from the white-rot fungus ''Schizophyllum commune'', and the activity was demonstrated by TLC on a methyl ester of 4-''O''-methyl-D-glucuronic acid <cite>Spanikova2006</cite>. While CE15 members are found in both fungal and bacterial species, several bacterial CE15 enzymes are more promiscuous than their fungal counterparts and are active also on esters of galacturonoate <cite>Arnlingbaath2018</cite>. Feruloyl- and acetyl esterase activities have been reported for certain CE15 enzymes as side activities <cite>Desanti2016 Mosbech2018</cite>. The proposed physiological role of CE15 enzymes is to hydrolyze lignin-carbohydrate ester linkages between lignin and glucuronoxylan in plant cell walls, and a few studies have demonstrated their activity on lignocellulose-derived materials and plant biomass <cite>Derrico2016 Arnlingbaath2016 Mosbech2018 </cite>.
== Catalytic Residues and Mechanism ==
All CE15 enzymes are serine-type hydrolases, containing a catalytic triad of Glu/Asp-His-Ser <cite>Pokkuluri2011 Charavgi2013 Desanti2017 Arnlingbaath2018</cite>. The position of the acidic residue of the triad is not similarly positioned in all CE15 members as the residue can be found on different loops of the conserved fold <cite>Desanti2017</cite>. A conserved arginine found in all of the CE15 structures, proximal to the catalytic triad, has been proposed to stabilize the formation of the oxyanion during catalysis <cite>Arnlingbaath2018 Mazurkewich2019 Zong2022</cite>.

== Three-dimensional structures ==
Representative structures of CE15 enzymes from bacterial and fungal sources have been determined, including ''Tr''GE (Cip2) from ''T. reesei'' (''Hypocrea jecorina'', PDB [{{PDBlink}}3pic 3pic]) <cite>Pokkuluri2011</cite>, ''St''GE2 from ''Thermothelomyces thermophila'' (''Sporotrichum thermophile'', PDB [{{PDBlink}}4g4g 4g4g], [{{PDBlink}}4g4i 4g4i], and [{{PDBlink}}4g4j 4g4j]) <cite>Charavgi2013</cite>, marine metagenome sequence MZ0003 (PDB [{{PDBlink}}6ehn 6ehn]) <cite>Desanti2017</cite>, ''Ot''CE15A (PDB [{{PDBlink}}6grw 6grw] and [{{PDBlink}}6gs0 6gs0]) and ''Su''CE15C (PDB [{{PDBlink}}6gry 6gry] and [{{PDBlink}}6gu8 6gu8]) <cite>Arnlingbaath2018</cite> (see the CAZy database for a [http://www.cazy.org/CE15_structure.html continuously updated list]). All structurally determined CE15 enzymes share an alpha/beta hydrolase fold, consisting of a three-layer alpha-beta-alpha sandwich with the active site in a solvent-exposed cleft. The structures of the bacterial enzymes determined thus far exhibit sizeable inserts which result in much deeper active site pockets compared to the shallow active sites seen in fungal glucuronoyl esterase structures <cite>Desanti2017 Arnlingbaath2018 </cite>. The first structures with a more complex ligand than a monosaccharide were of the bacterial ''Ot''CE15A (PDB [{{PDBlink}}6t0i 6t0i]) with a glucuronoxylooligosaccharide <cite>Mazurkewich2019</cite>, which was followed by a similar structure of the fungal ''Cu''GE from ''Cerrena unicolor'' (PDB [{{PDBlink}}6rv9 6rv9]).

== Family Firsts ==
;First 3-D structure: The first solved structure of a CE15 enzyme was the Cip2 catalytic domain from ''Trichoderma reesei'' (''Tr''GE) <cite>Pokkuluri2011</cite>.
;First mechanistic insight: The crystal structure of ''St''GE2 (from ''Sporotrichum thermophile'') in complex with the ligand 4-''O''-methyl-beta-D-glucopyranuronate gave the first direct insight into substrate binding <cite>Charavgi2013</cite>.

== References ==
<biblio>
#Spanikova2006 pmid=16876163
#Arnlingbaath2018 pmid=30083226
#Desanti2016 pmid=27433797
#Mosbech2018 pmid=29560026
#Derrico2016 pmid=26712478
#Arnlingbaath2016 pmid=27397104
#Pokkuluri2011 pmid=21661060
#Charavgi2013 pmid=23275164
#Desanti2017 pmid=29222424
#Mazurkewich2019 pmid=31740581
#Zong2022 pmid=35304453
#Ernst2020 pmid=32094331

</biblio>

[[Category:Carbohydrate Esterase Families|CE015]]

User:Johan Larsbrink

2023-08-16T14:48:41Z

Johan Larsbrink:

[[Image:JLarsbrink.jpg|thumb|200px|right]]
'''Associate Professor''' at the Department of Life Sciences, [http://www.chalmers.se Chalmers University of Technology].

== Background ==

I obtained a MSc degree in Biotechnology at the [http://www.kth.se Royal Institute of Technology (KTH)] in 2007, where I later also completed my PhD thesis under the supervision of [[User:Harry Brumer|Harry Brumer]], focusing on xyloglucan degradation <cite>Larsbrink2011 Larsbrink2014a Larsbrink2014b</cite>. After my PhD I worked as a postdoctoral fellow with Phil Pope and [[User:Vincent Eijsink|Vincent Eijsink]] at the [http://www.nmbu.no Norwegian University of Life Sciences (NMBU)], mainly on chitin degradation <cite>Larsbrink2016</cite>. In 2015 I was appointed Assistant Professor at Chalmers University of Technology, and in 2019 I was promoted to Associate Professor. My research focuses primarily on enzyme (CAZyme) discovery coupled to structural and biochemical characterization.

I have contributed to structure-function studies of CAZymes from various families, including [[GH5]] <cite>Larsbrink2014a</cite>, [[GH18]] <cite>Mazurkewich2020</cite>, [[GH31]] <cite>Larsbrink2011 Larsbrink2012 Larsbrink2014a</cite>, [[GH35]] <cite>Larsbrink2014b</cite>, and [[CE15]] <cite>JAB2018 JAB2019 Mazurkewich2019 Krska2021 Zong2022</cite>.

== Selected papers ==

<biblio>

#Larsbrink2011 pmid=21426303
#Larsbrink2012 pmid=23132856
#Larsbrink2014a pmid=24463512
#Larsbrink2014b pmid=25171165
#Larsbrink2016 pmid=27933102
#JAB2018 pmid=30083226
#JAB2019 pmid=30814248
#Mazurkewich2019 pmid=31740581
#Mazurkewich2020 pmid=32792608
#Krska2021 pmid=34180241
#Zong2022 pmid=35304453

</biblio>


[[Category:Contributors|Larsbrink,Johan]]

Carbohydrate Binding Module Family 9

2023-08-16T13:59:16Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T13:57:40Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T13:53:45Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T13:48:34Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:55:31Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:54:17Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:52:42Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:52:23Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:51:08Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:49:30Z

Johan Larsbrink:

File:Fig.1 CBM9.jpg

2023-08-16T10:43:43Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:41:27Z

Johan Larsbrink:

Carbohydrate Binding Module Family 9

2023-08-16T10:39:10Z

Johan Larsbrink:

User:Johan Larsbrink

2019-08-26T14:19:20Z

Johan Larsbrink:

[[Image:JLarsbrink.jpg|thumb|200px|right]]
'''Associate Professor''' at the Department of Biology and Biological Engineering, [http://www.chalmers.se Chalmers University of Technology].

== Background ==

I obtained a MSc degree in Biotechnology at the [http://www.kth.se Royal Institute of Technology (KTH)] in 2007, where I later also completed my PhD thesis under the supervision of ^^^Harry Brumer^^^, focusing on xyloglucan degradation <cite>Larsbrink2011 Larsbrink2014a Larsbrink2014b</cite>. After my PhD I worked as a postdoctoral fellow with Phil Pope and ^^^Vincent Eijsink^^^ at the [http://www.nmbu.no Norwegian University of Life Sciences (NMBU)], mainly on chitin degradation <cite>Larsbrink2016</cite>. In 2015 I was appointed Assistant Professor at Chalmers University of Technology, and in 2019 I was promoted to Associate Professor. My research focuses primarily on enzyme (CAZyme) discovery coupled to structural and biochemical characterization.

I have contributed to structure-function studies of CAZymes from various families, including [[GH5]] <cite>Larsbrink2014a</cite>, [[GH18]], [[GH31]] <cite>Larsbrink2011 Larsbrink2012 Larsbrink2014a</cite>, [[GH35]] <cite>Larsbrink2014b</cite>, and [[CE15]] <cite>JAB2018 JAB2019</cite>.

== Selected papers ==

<biblio>

#Larsbrink2011 pmid=21426303
#Larsbrink2012 pmid=23132856
#Larsbrink2014a pmid=24463512
#Larsbrink2014b pmid=25171165
#Larsbrink2016 pmid=27933102
#JAB2018 pmid=30083226
#JAB2019 pmid=30814248

</biblio>


[[Category:Contributors|Larsbrink,Johan]]

Carbohydrate Esterase Family 15

2019-07-15T11:19:27Z

Johan Larsbrink:

{{CuratorApproved}}
* [[Author]]: ^^^Jenny Arnling Bååth^^^ and ^^^Scott Mazurkewich^^^
* [[Responsible Curator]]: ^^^Johan Larsbrink^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Carbohydrate Esterase Family CE15'''
|-
|'''Clan'''
|GH-x
|-
|'''Mechanism'''
|retaining/inverting
|-
|'''Active site residues'''
|known/not known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}CE15.html
|}
</div>


[[File: CE15_CAZypedia_Figure.png|thumb|right|400px|'''Figure 1. Comparison of structurally determined CE15 members.''' The CE15s (A) ''St''GE2 from ''Thermothelomyces thermophila'' (PDB ID [{{PDBlink}}4g4j 4G4J]), (B) ''Ot''CE15A from ''Opitutus terrae'' (PDB ID [{{PDBlink}}6gs0 6GS0]), and (C) ''Tt''CE15A from ''Teredinibacter turnerae'' (PDB ID [{{PDBlink}}6hsw 6HSW]) are shown in cartoon representation. The catalytic triad in each enzyme is shown as sticks and the methyl ester of 4-''O''-methyl glucuronoate first observed in ''St''GE2 is shown in all structures as green sticks. While all CE15 members contain the alpha/beta hydrolase fold, the most prominent difference across the CE15 family observed to-date are the presence, absence, or variety of inserted regions that protrude and build-up ridges around the active site (the differently colored regions in the ''Ot''CE15A and ''Tt''CE15A). The extent to which these regions affect the enzyme’s substrate specificity has yet to be fully elucidated.]]

== Substrate specificity ==
All CE15 enzymes characterized to-date are glucuronoyl esterases, cleaving esters of D-glucuronic acid. The first reported glucuronoyl esterase was ''Sc''GE1 from the white-rot fungus ''Schizophyllum commune'', and the activity was demonstrated by TLC on a methyl ester of 4-''O''-methyl-D-glucuronic acid <cite>Spanikova2006</cite>. While CE15 members are found in both fungal and bacterial species, several bacterial CE15 enzymes are more promiscuous than their fungal counterparts and are active also on esters of galacturonoate <cite>Arnlingbaath2018</cite>. Feruloyl- and acetyl esterase activities have been reported for certain CE15 enzymes as side activities <cite>Desanti2016 Mosbech2018</cite>. The proposed physiological role of CE15 enzymes is to hydrolyze lignin-carbohydrate ester linkages between lignin and glucuronoxylan in plant cell walls, and a few studies have demonstrated their activity on lignocellulose-derived materials and plant biomass <cite>Derrico2016 Arnlingbaath2016 Mosbech2018 </cite>.

== Three-dimensional structures ==
Representative structures of CE15 enzymes from bacterial and fungal sources have been determined, including ''Tr''GE (Cip2) from ''T. reesei'' (''Hypocrea jecorina'', PDB [{{PDBlink}}3pic 3pic]) <cite>Pokkuluri2011</cite>, ''St''GE2 from ''Thermothelomyces thermophila'' (''Sporotrichum thermophile'', PDB [{{PDBlink}}4g4g 4g4g], [{{PDBlink}}4g4i 4g4i], and [{{PDBlink}}4g4j 4g4j]) <cite>Charavgi2013</cite>, marine metagenome sequence MZ0003 (PDB [{{PDBlink}}6ehn 6ehn]) <cite>Desanti2017</cite>, ''Ot''CE15A (PDB [{{PDBlink}}6grw 6grw] and [{{PDBlink}}6gs0 6gs0]) and ''Su''CE15C (PDB [{{PDBlink}}6gry 6gry] and [{{PDBlink}}6gu8 6gu8]) <cite>Arnlingbaath2018</cite> (see the CAZy database for a [http://www.cazy.org/CE15_structure.html continuously updated list]). All structurally determined CE15 enzymes share an alpha/beta hydrolase fold, consisting of a three-layer alpha-beta-alpha sandwich with the active site in a solvent-exposed cleft. The structures of the bacterial enzymes determined thus far exhibit sizeable inserts which result in much deeper active site pockets compared to the shallow active sites seen in fungal glucuronoyl esterase structures <cite>Desanti2017 Arnlingbaath2018 </cite>.

== Catalytic Residues and Mechanism ==
All CE15 enzymes are serine-type hydrolases, containing a catalytic triad of Glu/Asp-His-Ser <cite>Pokkuluri2011 Charavgi2013 Desanti2017 Arnlingbaath2018</cite>. The position of the acidic residue of the triad is not similarly positioned in all CE15 members as the residue can be found on different loops of the conserved fold <cite>Desanti2017</cite>. A conserved arginine found in all of the CE15 structures, proximal to the catalytic triad, has been proposed to stabilize the formation of the oxyanion during catalysis <cite>Arnlingbaath2018</cite>.

== Family Firsts ==
;First 3-D structure: The first solved structure of a CE15 enzyme was the Cip2 catalytic domain from ''Trichoderma reesei'' (''Tr''GE) <cite>Pokkuluri2011</cite>.
;First mechanistic insight: The crystal structure of ''St''GE2 (from ''Sporotrichum thermophile'') in complex with the ligand 4-''O''-methyl-beta-D-glucopyranuronate gave the first direct insight into substrate binding <cite>Charavgi2013</cite>.

== References ==
<biblio>
#Spanikova2006 pmid=16876163
#Arnlingbaath2018 pmid=30083226
#Desanti2016 pmid=27433797
#Mosbech2018 pmid=29560026
#Derrico2016 pmid=26712478
#Arnlingbaath2016 pmid=27397104
#Pokkuluri2011 pmid=21661060
#Charavgi2013 pmid=23275164
#Desanti2017 pmid=29222424
</biblio>

[[Category:Carbohydrate Esterase Families|CE015]]

User:Johan Larsbrink

2018-11-13T19:41:19Z

Johan Larsbrink:

[[Image:JLarsbrink.jpg|thumb|200px|right]]
'''Assistant Professor''' at the Department of Biology and Biological Engineering, [http://www.chalmers.se Chalmers University of Technology].

== Background ==

I obtained a MSc degree in Biotechnology at the [http://www.kth.se Royal Institute of Technology (KTH)] in 2007, where I later also completed my PhD thesis under the supervision of ^^^Harry Brumer^^^, focusing on xyloglucan degradation <cite>Larsbrink2011 Larsbrink2014a Larsbrink2014b</cite>. After working as a postdoctoral fellow with Phil Pope and ^^^Vincent Eijsink^^^ at the [http://www.nmbu.no Norwegian University of Life Sciences (NMBU)], working on chitin degradation <cite>Larsbrink2016</cite>, I was in 2015 appointed Assistant Professor at Chalmers University of Technology. My research focuses primarily on enzyme (CAZyme) discovery coupled to structural and biochemical characterization.

I have contributed to structure-function studies of CAZymes from various families, including [[GH5]] <cite>Larsbrink2014a</cite>, [[GH18]], [[GH31]] <cite>Larsbrink2011 Larsbrink2012 Larsbrink2014a</cite>, [[GH35]] <cite>Larsbrink2014b</cite>, and [[CE15]] <cite>JAB2018</cite>.

== Selected papers ==

<biblio>

#Larsbrink2011 pmid=21426303
#Larsbrink2012 pmid=23132856
#Larsbrink2014a pmid=24463512
#Larsbrink2014b pmid=25171165
#Larsbrink2016 pmid=27933102
#JAB2018 pmid=30083226

</biblio>


[[Category:Contributors|Larsbrink,Johan]]

File:JLarsbrink.jpg

2018-11-13T19:11:23Z

Johan Larsbrink: