3A3H

CELLOTRIOSE COMPLEX OF THE ENDOGLUCANASE CEL5A FROM BACILLUS AGARADHERANS AT 1.6 A RESOLUTION

3A3H の概要

• エントリーDOI: 10.2210/pdb3a3h/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900014
• 分子名称: ENDOGLUCANASE, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose-(1-4)-alpha-D-glucopyranose (3 entities in total)
• 機能のキーワード: hydrolase, cellulose degradation, endoglucanase, glycoside hydrolase family 5
• 由来する生物種: Bacillus agaradhaerens
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 34158.18

構造登録者

Davies, G.J.,Brzozowski, A.M.,Andersen, K.,Schulein, M. (登録日: 1998-02-01, 公開日: 1999-03-16, 最終更新日: 2024-02-21)

主引用文献

Davies, G.J.,Mackenzie, L.,Varrot, A.,Dauter, M.,Brzozowski, A.M.,Schulein, M.,Withers, S.G.
Snapshots along an enzymatic reaction coordinate: analysis of a retaining beta-glycoside hydrolase.
Biochemistry, 37:11707-11713, 1998

PubMed Abstract: The enzymatic hydrolysis of O-glycosidic linkages is one of the most diverse and widespread reactions in nature and involves a classic "textbook" enzyme mechanism. A multidisciplinary analysis of a beta-glycoside hydrolase, the Cel5A from Bacillus agaradhaerens, is presented in which the structures of each of the native, substrate, covalent-intermediate, and product complexes have been determined and their interconversions analyzed kinetically, providing unprecedented insights into the mechanism of this enzyme class. Substrate is bound in a distorted 1S3 skew-boat conformation, thereby presenting the anomeric carbon appropriately for nucleophilic attack as well as satisfying the stereoelectronic requirements for an incipient oxocarbenium ion. Leaving group departure results in the trapping of a covalent alpha-glycosyl-enzyme intermediate in which the sugar adopts an undistorted 4C1 conformation. Finally, hydrolysis of this intermediate yields a product complex in which the sugar is bound in a partially disordered mode, consistent with unfavorable interactions and low product affinity.

PubMed: 9718293
DOI: 10.1021/bi981315i

実験手法

X-RAY DIFFRACTION (1.64 Å)