User:Tracey Gloster

2009-10-06T20:31:49Z

2009-10-02T19:50:39Z

Tracey Gloster:

Glycoside Hydrolase Family 97

2009-10-02T19:44:50Z

Tracey Gloster:

{{UnderConstruction}}
* [[Author]]: ^^^Tracey Gloster^^^
* [[Responsible Curator]]: ^^^Gideon Davies^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH97'''
|-
|'''Clan'''
|Not assigned
|-
|'''Mechanism'''
|Retaining and Inverting
|-
|'''Active site residues'''
|Inferred
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |http://www.cazy.org/fam/GH97.html
|}
</div>


== Substrate specificities ==
Family 97 [[glycoside hydrolases]] hydrolyse α-linked substrates; the two enzymes from this family that have been characterised to date have α-glucosidase (EC 3.2.1.20) and α-galactosidase (EC 3.2.1.22) activity <cite>REF1</cite>. The alpha-glucosidase from ''Bacteroides thetaiotaomicron'' has been characterised in the most detail, and has been demonstrated to hydrolyse substrates ranging from maltose to maltoheptaose in length, and those containing α-1,6-, α-1,3- and α-1,2-, as well as α-1,4-, linkages <cite>REF2;REF3</cite>.

== Kinetics and Mechanism ==
Family GH97 is unusual as it contains both [[retaining]] and [[inverting]] enzymes, as shown unequivocally by NMR <cite>REF1</cite> and HPLC <cite>REF3</cite>, by characterization of two enzymes from ''Bacteroides thetaiotaomicron''. Both mechanisms are strongly dependent on the presence of calcium, which coordinates the C2-OH group of the substrate in the -1 subsite, as well as four glutamate residues in the active site <cite>REF1</cite>. One of the glutamate residues coordinated by the calcium ion is predicted to be the [[general acid/base]] residue, which may receive acid assistance from the calcium during hydrolysis.

== Catalytic Residues ==

== Three-dimensional structures ==
There has been one structure solved, using X-ray crystallography, for a member of family GH97. This is an enzyme from ''Bacteroides thetaiotaomicron'', SusB, which is involved in the degradation of starch degradation in the human gut. The tertiary structure of the GH97 enzyme revealed three domains; an N-terminal β-super-sandwich domain, followed by a canonical (β/α)8 barrel (which houses the catalytic domain) and a C-terminal β-sheet domain <cite>REF1;REF3</cite>. There have also been complexes solved with the inhibitors acarbose <cite>REF3</cite>, deoxynojirimycin and castanospermine <cite>REF1</cite>. Structural alignments show similarity to families GH27 and GH36 (as predicted previously by a bioinformatics study <cite>REF4</cite>).

== Family Firsts ==
;First sterochemistry determination: Two GH97 members from ''Bacteroides thetaiotaomicron'' were shown to differ in stereochemical outcome, by NMR <cite>REF1</cite> and HPLC <cite>REF3</cite>, demonstrating the family contains enzymes which hydrolyse with both retention and inversion of stereochemistry.
;First catalytic nucleophile identification: Not proven unequivocally (although has been predicted using structure and sequence alignments, see <cite>REF1</cite>).
;First general acid/base residue identification: Not proven unequivocally (although has been predicted using structure and sequence alignments, see <cite>REF1</cite>).
;First 3-D structure: A GH97 member from ''Bacteroides thetaiotaomicron'', SusB, was solved using X-ray crystallography by two groups <cite>REF1;REF3</cite>.

== References ==
<biblio>
#REF1 pmid=18848471
#REF2 pmid=1708385
#REF3 pmid=18981178
#REF4 pmid=16131397

</biblio>


<nowiki>[[Category:Glycoside Hydrolase Families|GHnnn]]</nowiki>

Glycoside Hydrolase Family 97

2009-10-02T19:42:14Z

Tracey Gloster:

{{UnderConstruction}}
* [[Author]]: ^^^Tracey Gloster^^^
* [[Responsible Curator]]: ^^^Gideon Davies^^^
----


<div style="float:right">
{| {{Prettytable}}
|-
|{{Hl2}} colspan="2" align="center" |'''Glycoside Hydrolase Family GH97'''
|-
|'''Clan'''
|Not assigned
|-
|'''Mechanism'''
|Retaining and Inverting
|-
|'''Active site residues'''
|Inferred
|-
|{{Hl2}} colspan="2" align="center" |'''CAZy DB link'''
|-
| colspan="2" |http://www.cazy.org/fam/GH97.html
|}
</div>


== Substrate specificities ==
Family 97 [[glycoside hydrolases]] hydrolyse α-linked substrates; the two enzymes from this family that have been characterised to date have α-glucosidase (EC 3.2.1.20) and α-galactosidase (EC 3.2.1.22) activity <cite>REF1</cite>. The alpha-glucosidase from ''Bacteroides thetaiotaomicron'' has been characterised in the most detail, and has been demonstrated to hydrolyse substrates ranging from maltose to maltoheptaose in length, and those containing α-1,6-, α-1,3- and α-1,2-, as well as α-1,4-, linkages <cite>REF2;REF3</cite>.

== Kinetics and Mechanism ==
Family GH97 is unusual as it contains both [[retaining]] and [[inverting]] enzymes, as shown unequivocally by NMR <cite>REF1</cite> and HPLC <cite>REF3</cite>, by characterization of two enzymes from ''Bacteroides thetaiotaomicron''. Both mechanisms are strongly dependent on the presence of calcium, which coordinates the C2-OH group of the substrate in the -1 subsite, as well as four glutamate residues in the active site <cite>REF1</cite>. One of the glutamate residues coordinated by the calcium ion is predicted to be the [[general acid/base]] residue, which may receive acid assistance from the calcium during hydrolysis.

== Catalytic Residues ==
Content is to be added here.

== Three-dimensional structures ==
There has been one structure solved, using X-ray crystallography, for a member of family GH97. This is an enzyme from ''Bacteroides thetaiotaomicron'', SusB, which is involved in the degradation of starch degradation in the human gut. The tertiary structure of the GH97 enzyme revealed three domains; an N-terminal β-super-sandwich domain, followed by a canonical (β/α)8 barrel (which houses the catalytic domain) and a C-terminal β-sheet domain <cite>REF1;REF3</cite>. There have also been complexes solved with the inhibitors acarbose <cite>REF3</cite>, deoxynojirimycin and castanospermine <cite>REF1</cite>. Structural alignments show similarity to families GH27 and GH36 (as predicted previously by a bioinformatics study <cite>REF4</cite>.

== Family Firsts ==
;First sterochemistry determination: Two GH97 members from ''Bacteroides thetaiotaomicron'' were shown to differ in stereochemical outcome, by NMR <cite>REF1</cite> and HPLC <cite>REF3</cite>, demonstrating the family contains enzymes which hydrolyse with both retention and inversion of stereochemistry.
;First catalytic nucleophile identification: Not proven unequivocally (although has been predicted using structure and sequence alignments, see <cite>REF1</cite>).
;First general acid/base residue identification: Not proven unequivocally (although has been predicted using structure and sequence alignments, see <cite>REF1</cite>).
;First 3-D structure: A GH97 member from ''Bacteroides thetaiotaomicron'', SusB, was solved using X-ray crystallography by two groups <cite>REF1;REF3</cite>.

== References ==
<biblio>
#REF1 pmid=18848471
#REF2 pmid=1708385
#REF3 pmid=18981178
#REF4 pmid=16131397

</biblio>


<nowiki>[[Category:Glycoside Hydrolase Families|GHnnn]]</nowiki>

Glycoside Hydrolase Family 97

2009-10-02T19:27:06Z

2009-10-01T17:48:20Z

Tracey Gloster:

I obtained a BSc in Biochemistry from the University of Warwick in 2002, and then moved to the University of York to study for a PhD, under the supervision of Gideon Davies. The work focussed on the inhibition of glycoside hydrolases, in particular those from families GH1, GH5 and GH10, where we attempted to understand aspects of ‘transition state mimicry’ using a combination of X-ray crystallography, enzyme kinetics and isothermal titration calorimetry. After a short post-doc in the same lab, where I investigated the structure and function of a number of other glycoside hydrolases, carbohydrate esterases and carbohydrate binding modules, I obtained a Sir Henry Wellcome post-doctoral fellowship, funded by the Wellcome Trust, UK. This fellowship provided me with the opportunity to move to Simon Fraser University, Burnaby, BC, to work with David Vocadlo, where currently we are investigating aspects of the O-GlcNAc post-translational modification.

User:Tracey Gloster

2009-10-01T17:47:06Z

Tracey Gloster: Created page with ' Normal 0 false false false EN-GB X-NONE X-NONE MicrosoftInternetExplorer4 I obtained a BSc …'

Normal 0 false false false EN-GB X-NONE X-NONE MicrosoftInternetExplorer4

I obtained a BSc in Biochemistry from the University of Warwick in 2002, and then moved to the University of York to study for a PhD, under the supervision of Gideon Davies. The work focussed on the inhibition of glycoside hydrolases, in particular those from families GH1, GH5 and GH10, where we attempted to understand aspects of ‘transition state mimicry’ using a combination of X-ray crystallography, enzyme kinetics and isothermal titration calorimetry. After a short post-doc in the same lab, where I investigated the structure and function of a number of other glycoside hydrolases, carbohydrate esterases and carbohydrate binding modules, I obtained a Sir Henry Wellcome post-doctoral fellowship, funded by the Wellcome Trust, UK. This fellowship provided me with the opportunity to move to Simon Fraser University, Burnaby, BC, to work with David Vocadlo, where currently we are investigating aspects of the O-GlcNAc post-translational modification.