1AYX

CRYSTAL STRUCTURE OF GLUCOAMYLASE FROM SACCHAROMYCOPSIS FIBULIGERA AT 1.7 ANGSTROMS

1AYX の概要

• エントリーDOI: 10.2210/pdb1ayx/pdb
• 分子名称: GLUCOAMYLASE, 2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL (3 entities in total)
• 機能のキーワード: glucoamylase, hydrolase, glycosidase, polysaccharide degradation
• 由来する生物種: Saccharomycopsis fibuligera
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 54782.11

構造登録者

Sevcik, J.,Hostinova, E.,Gasperik, J.,Solovicova, A.,Wilson, K.S.,Dauter, Z. (登録日: 1997-11-12, 公開日: 1998-05-13, 最終更新日: 2024-02-07)

主引用文献

Sevcik, J.,Solovicova, A.,Hostinova, E.,Gasperik, J.,Wilson, K.S.,Dauter, Z.
Structure of glucoamylase from Saccharomycopsis fibuligera at 1.7 A resolution.
Acta Crystallogr.,Sect.D, 54:854-866, 1998

PubMed Abstract: 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.

PubMed: 9757101
DOI: 10.1107/S0907444998002005

実験手法

X-RAY DIFFRACTION (1.7 Å)