{{CuratorApproved}}
* [[Author]]s: ^^^Ramon Hurtado-Guerrero^^^ and ^^^Thierry Fontaine^^^
* [[Responsible Curator]]: ^^^Bernard Henrissat^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH72'''
|-
|'''Clan'''
|none, (βα)8 fold
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH72.html
|}
</div>


== Substrate specificities ==
The GH72 family is formed exclusively by [[transglycosylases]] of the fungal kindgom whose activity was firstly characterized in ''Aspergillus fumigatus'' <cite>Hartland1996</cite> and yeasts <cite>Mouyna2000 Carotti2004 deMedina-Redondo2008</cite>. These GPI-anchored plasma membrane enzymes elongate and remodel the β-1,3 glucan of the cell wall <cite>Mouyna2000a Mouyna2005 Gastebois2010 deMedina-Redondo2008 deMedina-Redondo2010 Ragni2007a</cite>. This activity is due to their catalytic domain is located in the external part of the plasma membrane. Two sub-families have been described for GH72 family members depending on the presence or absence of a C-terminal cysteine rich domain (carbohydrate binding domain, [[CBM43]]) in addition to the catalytic domain <cite>Ragni2007b</cite>.

== Kinetics and Mechanism ==
The catalysis by GH72 family enzymes occurs via a classical Koshland retaining mechanism, which leads to net retention of the β-anomeric configuration of the final product. Enzymatic kinetics were determined by HPLC and showed that these enzymes are [[transglycosylases]] rather than [[glycoside hydrolases]]. These enzymes cleave internally a β-1,3-glucan molecule and transfer the newly generated reducing end to the non-reducing end of a second β-1,3-glucan molecule through a β-1,3-linkage, resulting in the elongation of the chain. The minimum size of the donor and acceptor substrates described in few fungal species are laminaridecaose and laminaripentaose, respectively <cite>Hartland1996 Mazan2011</cite>.
Despite that the overall mechanisms of [[glycoside hydrolases|hydrolysis]] and [[transglycosylases|transglycosylation]] are well known, it is still unclear how [[transglycosylases]] limit or prevent hydrolysis in aqueous media, where the concentration of water is 55 M. By structural studies with different laminarioligosaccharides and enzymatic activity assays, a “base occlusion mechanism”, in which the acceptor sugar blocks the entrance of water molecules, was proposed to explain this phenomenon <cite>Hurtado-Guerrero2009</cite>.

== Catalytic Residues ==
Multiple sequence alignments have highlighted conserved amino acid between GH72 family members <cite>Mouyna2000b</cite>. Hydrophobic cluster analysis allowed to identify two highly conserved glutamate residues in the region comparable to the C-terminal end of strands β-4 and β-7 of ''Clostridium cellulolyticum'' endoglucanase A (a [[GH5]] member) <cite>Mouyna2000</cite>. Site-direct mutagenesis of these two glutamate residues in ''A. fumigatus'' Gel1p and ''S. cerevisiae'' Gas1p have shown their essentiality for the transglycosidase activity <cite>Mouyna2000b Carotti2004</cite> and support that these residues are the acid-base and nucleophilic residues responsible for the catalytic mechanism. The identity of these residues were further confirmed by the resolution of the crystal structure of S. cerevisiae Gas2 (ScGas2) [[File:Gas2.pdf|200px|thumb|left|alt text]] (see below) <cite>Hurtado-Guerrero2009</cite>.

== Three-dimensional structures ==
The only three-dimensional structure available is that of ScGas2 [[File:Gas2.pdf|200px|thumb|left|alt text]]. The enzyme folds as a (beta/alpha)<sub>8</sub> barrel similar to that prevailing in other families constituting Clan GH-A <cite>Hurtado-Guerrero2009</cite>. The full length enzyme also harbors a [[CBM43]] module at the C-terminus. The crystal structure also showed that both domains share extensive contacts <cite>Hurtado-Guerrero2009</cite>.

== Family Firsts ==
;First stereochemistry determination:
β-1,3-glucanosyltransglycosilase (Gel1p) from ''Aspergillus fumigatus'' <cite>Hartland1996</cite>
;First catalytic nucleophile identification:
Shown in the β-1,3-glucanosyltransglycosilase (Gel1p) from ''Aspergillus fumigatus'' <cite>Mouyna2000b</cite>
;First general acid/base residue identification:
Shown in the β-1,3-glucanosyltransglycosilase (Gel1p) from ''Aspergillus fumigatus'' <cite>Mouyna2000b</cite>
;First 3-D structure: ScGas2 crystal structure <cite>Hurtado-Guerrero2009</cite>

== References ==
<biblio>
#Hartland1996 pmid=8900166
#Mouyna2000 pmid=10809732
#Carotti2004 pmid=15355340
#deMedina-Redondo2008 pmid=18410286
#Mouyna2000a pmid=10809732
#Mouyna2005 pmid=15916615
#Gastebois2010 pmid=20543062
#deMedina-Redondo2010 pmid=21124977
#Ragni2007a pmid=17189486
#Ragni2007b pmid=17397106
#Mazan2011 pmid=21651500
#Hurtado-Guerrero2009 pmid=19097997
#Mouyna2000b pmid=10769178

</biblio>

[[Category:Glycoside Hydrolase Families|GH072]]

2015-09-08T16:31:08Z

Ramon Hurtado-Guerrero:

{{UnderConstruction}}
* [[Author]]s: ^^^Ramon Hurtado-Guerrero^^^ and ^^^Thierry Fontaine^^^
* [[Responsible Curator]]: ^^^Bernard Henrissat^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH72'''
|-
|'''Clan'''
|none, (βα)8 fold
|-
|'''Mechanism'''
|retaining
|-
|'''Active site residues'''
|known
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |{{CAZyDBlink}}GH72.html
|}
</div>


== Substrate specificities ==
The GH72 family is formed exclusively by transglycosylases of the fungal kindgom whose activity was firstly characterized in Aspergillus fumigatus <cite>Hartland1996</cite> and yeasts <cite>Mouyna2000 Carotti2004 deMedina-Redondo2008</cite>. These GPI-anchored plasma membrane enzymes elongate and remodel the β-1,3 glucan of the cell wall <cite>Mouyna2000a Mouyna2005 Gastebois2010 deMedina-Redondo2008 deMedina-Redondo2010 Ragni2007a</cite>. This activity is due to their catalytic domain is located in the external part of the plasma membrane. Two sub-families have been described for GH72 family members depending on the presence or absence of a C-terminal cysteine rich domain (carbohydrate binding domain, CBM43) in addition to the catalytic domain <cite>Ragni2007b</cite>.

== Kinetics and Mechanism ==
The catalysis by GH72 family enzymes occurs via a classical Koshland retaining mechanism, which leads to net retention of the β-anomeric configuration of the final product. Enzymatic kinetics were determined by HPLC and showed that these enzymes are transglycosidases rather than glycoside hydrolases. These enzymes cleave internally a β-1,3-glucan molecule and transfer the newly generated reducing end to the non-reducing end of a second β-1,3-glucan molecule through a β-1,3-linkage, resulting in the elongation of the chain. The minimum size of the donor and acceptor substrates described in few fungal species are laminaridecaose and laminaripentaose, respectively <cite>Hartland1996 Mazan 2011</cite>.
Despite that the overall mechanism of hydrolysis and transglycosylation is well known, it is still unclear how transglycosylases can favor transglycosylation in a 55 M water medium. By structural studies with different laminarioligosaccharides and enzymatic activity assays, the “Base occlusion mechanism” was proposed to explain why these enzymes favor transglycosylation versus hydrolysis. In this mechanism, the acceptor sugar blocks the entrance of water molecules and thus avoids hydrolysis, favouring transglycosylation <cite>Hurtado-Guerrero2008</cite>.

== Catalytic Residues ==
Multiple sequence alignments have highlighted conserved amino acid between GH72 family members <cite>Mouyna2000b</cite>. Hydrophobic cluster analysis allowed to identify two highly conserved glutamate residues in the region comparable to the C-terminal end of strands β-4 and β-7 of the endoglucanase A (GH5 member) of Clostridium cellulolyticum <cite>Mouyna2000</cite>. Site-direct mutagenesis of these two glutamate residues in A. fumigatus Gel1p and S. cerevisiae Gas1p have shown their essentiality for the transglycosidase activity <cite>Mouyna2000b Carotti2004</cite> and support that these residues are the acid-base and nucleophilic residues responsible for the catalytic mechanism. The identity of these residues were further confirmed by the resolution of the crystal structure of S. cerevisiae Gas2 (ScGas2) (see below) <cite>HurtadoGuerrero2008</cite>.

== Three-dimensional structures ==
The only three-dimensional structure available is that of ScGas2. The enzyme folds as a (ba8 barrel similar to that prevailing in other families constituting Clan GH-A <cite>HurtadoGuerrero2008</cite> (Figure 1). The full length enzyme also harbors a CBM43 module at the C-terminus. The crystal structure also showed that both domains share extensive contacts <cite>HurtadoGuerrero2008</cite> (Figure 1).

== Family Firsts ==
;First stereochemistry determination:
β-1,3-glucanosyltransglycosilase (Gel1p) from Aspergillus fumigatus <cite>Hartland1996</cite>
;First catalytic nucleophile identification:
Shown in the β-1,3-glucanosyltransglycosilase (Gel1p) from Aspergillus fumigatus <cite>Mouyna2000b</cite>
;First general acid/base residue identification:
Shown in the β-1,3-glucanosyltransglycosilase (Gel1p) from Aspergillus fumigatus <cite>Mouyna2000b</cite>
;First 3-D structure: ScGas2 crystal structure <cite>HurtadoGuerrero2008</cite>

== References ==
<biblio>
#Hartland1996 pmid=8900166
#Mouyna2000 pmid=10809732
#Carotti2004 pmid=15355340
#deMedina-Redondo2008 pmid=18410286
#Mouyna2000a pmid=10809732
#Mouyna2005 pmid=15916615
#Gastebois2010 pmid=20543062
#deMedina-Redondo2010 pmid=21124977
#Ragni2007a pmid=17189486
#Ragni2007b pmid=17397106
#Mazan2011 pmid=21651500
#Hurtado-Guerrero2009 pmid=19097997

1591661510809732
10809732#3 isbn=9780240521183
#MikesClassic Sinnott, M.L. (1990) Catalytic mechanisms of enzymic glycosyl transfer. Chem. Rev. 90, 1171-1202. [http://dx.doi.org/10.1021/cr00105a006 DOI: 10.1021/cr00105a006]

</biblio>

[[Category:Glycoside Hydrolase Families|GH072]]

Glycoside Hydrolase Family 72

2015-09-08T16:04:12Z

Ramon Hurtado-Guerrero:

Glycoside Hydrolase Family 72

2015-08-19T17:50:12Z

Ramon Hurtado-Guerrero:

2015-07-31T18:47:00Z

Ramon Hurtado-Guerrero:

User:Ramon Hurtado-Guerrero

2015-07-31T18:45:40Z

Ramon Hurtado-Guerrero:

[[Image:Blank_user-200px.png|200px|right]] [[File:FotoRamón1.jpg]]
Ramon Hurtado-Guerrero obtained his B.Sc. in Pharmacy from the University of Granada and completed his PhD at the University of Granada, where he worked in Molecular Parasitology. Then, he moved to the University of Leeds as a postdoctoral researcher under the supervision of Prof. Mike McPherson, where he worked in the elucidation of how a self-postranslational modification in galactose oxidase occurred. Then, he moved to University College of London where he worked under the cosupervision of Prof. Vallance and the company "Unipath" to develop a kit to determine ADMA in blood samples.
Finally, his last postdoctoral position was in Prof. van Aalten´s lab at the University of Dundee. There, he was introduced to Structural Glycobiology where he adquired all his skills in Protein X-ray Crystallography. During this time he solved several crystal structures of transglycosylases such as Gas2, as well as chitinases and glycosyltransferases such as OGT and LpGT.
At the end of 2009, he started his own lab as an ARAID investigator at the University of Zaragoza and works in the fascinating world of enzymes that process carbohydrates and proteins/antibodies that recognise different types of sugars.

* 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.
* Add your publications in the list below using PubMed IDs and cite them in the text like this <cite>Hurtado-Guerrero2009</cite>.
* 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.

''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''

----

<biblio>
#Hurtado-Guerrero2009 pmid=19097997

</biblio>


[[Category:Contributors|Hurtado-Guerrero,Ramon]]

User:Ramon Hurtado-Guerrero

User:Ramon Hurtado-Guerrero

2015-07-31T18:18:02Z

Ramon Hurtado-Guerrero:

[[Image:Blank_user-200px.png|200px|right]]
'''This is an empty template to help you get started with composing your User page.'''

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.
[[File:Foto Ramón.jpg]]
Ramon Hurtado-Guerrero obtained his B.Sc. in Pharmacy from the University of Granada and completed his PhD at the University of Granada, where he worked in Molecular Parasitology. Then, he moved to the University of Leeds as a postdoctoral researcher under the supervision of Prof. Mike McPherson, where he worked in the elucidation of how a self-postranslational modification in galactose oxidase occurred. Then, he moved to University College of London where he worked under the cosupervision of Prof. Vallance and the company "Unipath" to develop a kit to determine ADMA in blood samples.
Finally, his last postdoctoral position was in Prof. van Aalten´s lab at the University of Dundee. There, he was introduced to Structural Glycobiology where he adquired all his skills in Protein X-ray Crystallography. During this time he solved several crystal structures of transglycosylases such as Gas2, as well as chitinases and glycosyltransferases such as OGT and LpGT.
At the end of 2009, he started his own lab as an ARAID investigator at the University of Zaragoza and works in the fascinating world of enzymes that process carbohydrates and proteins/antibodies that recognise different types of sugars.

* 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.
* Add your publications in the list below using PubMed IDs and cite them in the text like this <cite>Hurtado-Guerrero2009</cite>.
* 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.

''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''

----

<biblio>
#Hurtado-Guerrero2009 pmid=19097997

</biblio>


[[Category:Contributors|Hurtado-Guerrero,Ramon]]

File:Foto Ramón.jpg

2015-07-31T18:09:44Z

Ramon Hurtado-Guerrero:

User:Ramon Hurtado-Guerrero

2015-07-31T18:07:59Z

Ramon Hurtado-Guerrero:

[[Image:Blank_user-200px.png|200px|right]]
'''This is an empty template to help you get started with composing your User page.'''

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.

Ramon Hurtado-Guerrero obtained his B.Sc. in Pharmacy from the University of Granada and completed his PhD at the University of Granada, where he worked in Molecular Parasitology. Then, he moved to the University of Leeds as a postdoctoral researcher under the supervision of Prof. Mike McPherson, where he worked in the elucidation of how a self-postranslational modification in galactose oxidase occurred. Then, he moved to University College of London where he worked under the cosupervision of Prof. Vallance and the company "Unipath" to develop a kit to determine ADMA in blood samples.
Finally, his last postdoctoral position was in Prof. van Aalten´s lab at the University of Dundee. There, he was introduced to Structural Glycobiology where he adquired all his skills in Protein X-ray Crystallography. During this time he solved several crystal structures of transglycosylases such as Gas2, as well as chitinases and glycosyltransferases such as OGT and LpGT.
At the end of 2009, he started his own lab as an ARAID investigator at the University of Zaragoza and works in the fascinating world of enzymes that process carbohydrates and proteins/antibodies that recognise different types of sugars.

* 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.
* Add your publications in the list below using PubMed IDs and cite them in the text like this <cite>Hurtado-Guerrero2009</cite>.
* 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.

''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''

----

<biblio>
#Hurtado-Guerrero2009 pmid=19097997

</biblio>


[[Category:Contributors|Hurtado-Guerrero,Ramon]]

User:Ramon Hurtado-Guerrero

2015-07-31T18:00:20Z

Ramon Hurtado-Guerrero:

[[Image:Blank_user-200px.png|200px|right]]
'''This is an empty template to help you get started with composing your User page.'''

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.

Ramon Hurtado-Guerrero obtained his B.Sc. in Pharmacy from the University of Granada and completed his PhD at the University of Granada, where he worked in molecular parasitology. Then, he moved to the University of Leeds as a postdoctoral researcher under the supervision of Prof. Mike McPherson. Here, he worked in the elucidation of the mechanism of how a self-postranslational modification in galactose oxidase occurred. Then, he moved to University College of London where he worked under the cosupervision of Prof. Vallance and a company "Unipath" to develop a kit to determine ADMA in blood samples. Finally, my last postdoctoral position was in Prof. van Aalten´s lab at the University of Dundee. Here, I was introduced to the structural Glycobiology where I learnt all my skills in protein X-ray crystallography. During this time I solved several crystal structures of transglycosylases such as Gas2, chitinases and glycosyltransferases such as OGT and LpGT.
At the end of 2009, I started my own lab as an ARAID investigator at the University of Zaragoza where I still go on working in the fascinating world of enzymes that process carbohydrates or proteins/antibodies that recognise different type of sugars.

* 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.
* Add your publications in the list below using PubMed IDs and cite them in the text like this <cite>Hurtado-Guerrero2009</cite>.
* 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.

''More specific help on these steps is available from the links under the "For contributors" section of the left page menu.''

----

<biblio>
#Hurtado-Guerrero2009 pmid=19097997

</biblio>


[[Category:Contributors|Hurtado-Guerrero,Ramon]]