1DYS

Endoglucanase CEL6B from Humicola insolens

1DYS の概要

• エントリーDOI: 10.2210/pdb1dys/pdb
• 分子名称: ENDOGLUCANASE (2 entities in total)
• 機能のキーワード: cellulase, hydrolase, cellulose degradation, glycoside hydrolase family 6
• 由来する生物種: HUMICOLA INSOLENS
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 75571.66

構造登録者

Davies, G.J.,Brzozowski, A.M.,Dauter, M.,Varrot, A.,Schulein, M. (登録日: 2000-02-08, 公開日: 2001-02-08, 最終更新日: 2024-05-01)

主引用文献

Davies, G.J.,Brzozowski, A.M.,Dauter, M.,Varrot, A.,Schulein, M.
Structure and Function of Humicola Insolens Family 6 Cellulases: Structure of the Endoglucanase, Cel6B, at 1.6 A Resolution
Biochem.J., 348:201-, 2000

PubMed Abstract: Cellulases are traditionally classified as either endoglucanases or cellobiohydrolases on the basis of their respective catalytic activities on crystalline cellulose, which is generally hydrolysed more efficiently only by the cellobiohydrolases. On the basis of the Trichoderma reesei cellobiohydrolase II structure, it was proposed that the active-site tunnel of cellobiohydrolases permitted the processive hydrolysis of cellulose, whereas the corresponding endoglucanases would display open active-site clefts [Rouvinen, Bergfors, Teeri, Knowles and Jones (1990) Science 249, 380-386]. Glycoside hydrolase family 6 contains both cellobiohydrolases and endoglucanases. The structure of the catalytic core of the family 6 endoglucanase Cel6B from Humicola insolens has been solved by molecular replacement with the known T. reesei cellobiohydrolase II as the search model. Strangely, at the sequence level, this enzyme exhibits the highest sequence similarity to family 6 cellobiohydrolases and displays just one of the loop deletions traditionally associated with endoglucanases in this family. However, this enzyme shows no activity on crystalline substrates but a high activity on soluble substrates, which is typical of an endoglucanase. The three-dimensional structure reveals that the deletion of just a single loop of the active site, coupled with the resultant conformational change in a second 'cellobiohydrolase-specific' loop, peels open the active-site tunnel to reveal a substrate-binding groove.

PubMed: 10794732
DOI: 10.1042/BJ3480201

実験手法

X-RAY DIFFRACTION (1.6 Å)