1ayx
From Proteopedia
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==Overview== | ==Overview== | ||
| - | The yeast Saccharomycopsis fibuligera produces a glucoamylase which | + | The yeast Saccharomycopsis fibuligera produces a glucoamylase which belongs to sequence family 15 of glycosyl hydrolases. The structure of the non-glycosyl-ated recombinant enzyme has been determined by molecular replacement and refined against 1.7 A resolution synchrotron data to an R factor of 14.6%. This is the first report of the three-dimensional structure of a yeast family 15 glucoamylase. The refinement from the initial molecular-replacement model was not straightforward. It involved the use of an unrestrained automated refinement procedure (uARP) in combination with the maximum-likelihood refinement program REFMAC. The enzyme consists of 492 amino-acid residues and has 14 alpha-helices, 12 of which form an (alpha/alpha)6 barrel. It contains a single catalytic domain but no starch-binding domain. The fold of the molecule and the active site are compared to the known structure of the catalytic domain of a fungal family 15 glucoamylase and are shown to be closely similar. The active- and specificity-site residues are especially highly conserved. The model of the acarbose inhibitor from the analysis of the fungal enzyme fits tightly into the present structure. The active-site topology is a pocket and hydrolysis proceeds with inversion of the configuration at the anomeric carbon. The enzyme acts as an exo-glycosyl hydrolase. There is a Tris [2-amino-2-(hydroxymethyl)-1,3-propanediol] molecule acting as an inhibitor in the active-site pocket. |
==About this Structure== | ==About this Structure== | ||
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[[Category: Sevcik, J.]] | [[Category: Sevcik, J.]] | ||
[[Category: Solovicova, A.]] | [[Category: Solovicova, A.]] | ||
| - | [[Category: Wilson, K | + | [[Category: Wilson, K S.]] |
[[Category: TRS]] | [[Category: TRS]] | ||
[[Category: glucoamylase]] | [[Category: glucoamylase]] | ||
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[[Category: polysaccharide degradation]] | [[Category: polysaccharide degradation]] | ||
| - | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:49:46 2008'' |
Revision as of 09:49, 21 February 2008
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CRYSTAL STRUCTURE OF GLUCOAMYLASE FROM SACCHAROMYCOPSIS FIBULIGERA AT 1.7 ANGSTROMS
Overview
The yeast Saccharomycopsis fibuligera produces a glucoamylase which belongs to sequence family 15 of glycosyl hydrolases. The structure of the non-glycosyl-ated recombinant enzyme has been determined by molecular replacement and refined against 1.7 A resolution synchrotron data to an R factor of 14.6%. This is the first report of the three-dimensional structure of a yeast family 15 glucoamylase. The refinement from the initial molecular-replacement model was not straightforward. It involved the use of an unrestrained automated refinement procedure (uARP) in combination with the maximum-likelihood refinement program REFMAC. The enzyme consists of 492 amino-acid residues and has 14 alpha-helices, 12 of which form an (alpha/alpha)6 barrel. It contains a single catalytic domain but no starch-binding domain. The fold of the molecule and the active site are compared to the known structure of the catalytic domain of a fungal family 15 glucoamylase and are shown to be closely similar. The active- and specificity-site residues are especially highly conserved. The model of the acarbose inhibitor from the analysis of the fungal enzyme fits tightly into the present structure. The active-site topology is a pocket and hydrolysis proceeds with inversion of the configuration at the anomeric carbon. The enzyme acts as an exo-glycosyl hydrolase. There is a Tris [2-amino-2-(hydroxymethyl)-1,3-propanediol] molecule acting as an inhibitor in the active-site pocket.
About this Structure
1AYX is a Single protein structure of sequence from Saccharomycopsis fibuligera with as ligand. Active as Glucan 1,4-alpha-glucosidase, with EC number 3.2.1.3 Known structural/functional Site: . Full crystallographic information is available from OCA.
Reference
Structure of glucoamylase from Saccharomycopsis fibuligera at 1.7 A resolution., Sevcik J, Solovicova A, Hostinova E, Gasperik J, Wilson KS, Dauter Z, Acta Crystallogr D Biol Crystallogr. 1998 Sep 1;54(Pt 5):854-66. PMID:9757101
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