2fba
From Proteopedia
(New page: 200px<br /><applet load="2fba" size="450" color="white" frame="true" align="right" spinBox="true" caption="2fba, resolution 1.10Å" /> '''Glucoamylase from Sa...) |
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| - | [[Image:2fba.gif|left|200px]]<br /><applet load="2fba" size=" | + | [[Image:2fba.gif|left|200px]]<br /><applet load="2fba" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2fba, resolution 1.10Å" /> | caption="2fba, resolution 1.10Å" /> | ||
'''Glucoamylase from Saccharomycopsis fibuligera at atomic resolution'''<br /> | '''Glucoamylase from Saccharomycopsis fibuligera at atomic resolution'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Most glucoamylases (alpha-1,4-D-glucan glucohydrolase, EC 3.2.1.3) have | + | Most glucoamylases (alpha-1,4-D-glucan glucohydrolase, EC 3.2.1.3) have structures consisting of both a catalytic and a starch binding domain. The structure of a glucoamylase from Saccharomycopsis fibuligera HUT 7212 (Glu), determined a few years ago, consists of a single catalytic domain. The structure of this enzyme with the resolution extended to 1.1 A and that of the enzyme-acarbose complex at 1.6 A resolution are presented here. The structure at atomic resolution, besides its high accuracy, shows clearly the influence of cryo-cooling, which is manifested in shrinkage of the molecule and lowering the volume of the unit cell. In the structure of the complex, two acarbose molecules are bound, one at the active site and the second at a site remote from the active site, curved around Tyr464 which resembles the inhibitor molecule in the 'sugar tongs' surface binding site in the structure of barley alpha-amylase isozyme 1 complexed with a thiomalto-oligosaccharide. Based on the close similarity in sequence of glucoamylase Glu, which does not degrade raw starch, to that of glucoamylase (Glm) from S. fibuligera IFO 0111, a raw starch-degrading enzyme, it is reasonable to expect the presence of the remote starch binding site at structurally equivalent positions in both enzymes. We propose the role of this site is to fix the enzyme onto the surface of a starch granule while the active site degrades the polysaccharide. This hypothesis is verified here by the preparation of mutants of glucoamylases Glu and Glm. |
==About this Structure== | ==About this Structure== | ||
| - | 2FBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomycopsis_fibuligera Saccharomycopsis fibuligera] with TRS as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Glucan_1,4-alpha-glucosidase Glucan 1,4-alpha-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.3 3.2.1.3] Full crystallographic information is available from [http:// | + | 2FBA is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomycopsis_fibuligera Saccharomycopsis fibuligera] with <scene name='pdbligand=TRS:'>TRS</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Glucan_1,4-alpha-glucosidase Glucan 1,4-alpha-glucosidase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.2.1.3 3.2.1.3] Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2FBA OCA]. |
==Reference== | ==Reference== | ||
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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: (alpha-alpha)6 barrel]] | [[Category: (alpha-alpha)6 barrel]] | ||
[[Category: tris]] | [[Category: tris]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:19:40 2008'' |
Revision as of 15:19, 21 February 2008
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Glucoamylase from Saccharomycopsis fibuligera at atomic resolution
Overview
Most glucoamylases (alpha-1,4-D-glucan glucohydrolase, EC 3.2.1.3) have structures consisting of both a catalytic and a starch binding domain. The structure of a glucoamylase from Saccharomycopsis fibuligera HUT 7212 (Glu), determined a few years ago, consists of a single catalytic domain. The structure of this enzyme with the resolution extended to 1.1 A and that of the enzyme-acarbose complex at 1.6 A resolution are presented here. The structure at atomic resolution, besides its high accuracy, shows clearly the influence of cryo-cooling, which is manifested in shrinkage of the molecule and lowering the volume of the unit cell. In the structure of the complex, two acarbose molecules are bound, one at the active site and the second at a site remote from the active site, curved around Tyr464 which resembles the inhibitor molecule in the 'sugar tongs' surface binding site in the structure of barley alpha-amylase isozyme 1 complexed with a thiomalto-oligosaccharide. Based on the close similarity in sequence of glucoamylase Glu, which does not degrade raw starch, to that of glucoamylase (Glm) from S. fibuligera IFO 0111, a raw starch-degrading enzyme, it is reasonable to expect the presence of the remote starch binding site at structurally equivalent positions in both enzymes. We propose the role of this site is to fix the enzyme onto the surface of a starch granule while the active site degrades the polysaccharide. This hypothesis is verified here by the preparation of mutants of glucoamylases Glu and Glm.
About this Structure
2FBA 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 Full crystallographic information is available from OCA.
Reference
Structure of the complex of a yeast glucoamylase with acarbose reveals the presence of a raw starch binding site on the catalytic domain., Sevcik J, Hostinova E, Solovicova A, Gasperik J, Dauter Z, Wilson KS, FEBS J. 2006 May;273(10):2161-71. PMID:16649993
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