2A39

HUMICOLA INSOLENS ENDOCELLULASE EGI NATIVE STRUCTURE

2A39 の概要

• エントリーDOI: 10.2210/pdb2a39/pdb
• 分子名称: ENDOGLUCANASE I, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total)
• 機能のキーワード: endoglucanase, hydrolase, cellulase, cellulose degradation, glycoside hydrolase family 7, glycosylated protein
• 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: 89108.06

構造登録者

Davies, G.J.,Sulzenbacher, G.,Mackenzie, L.,Withers, S.G.,Divne, C.,Jones, T.A.,Woldike, H.F.,Schulein, M. (登録日: 1998-01-30, 公開日: 1999-02-16, 最終更新日: 2024-11-13)

主引用文献

MacKenzie, L.F.,Sulzenbacher, G.,Divne, C.,Jones, T.A.,Woldike, H.F.,Schulein, M.,Withers, S.G.,Davies, G.J.
Crystal structure of the family 7 endoglucanase I (Cel7B) from Humicola insolens at 2.2 A resolution and identification of the catalytic nucleophile by trapping of the covalent glycosyl-enzyme intermediate.
Biochem.J., 335:409-416, 1998

PubMed Abstract: Cellulose is the major polysaccharide component of the plant cell wall and the most abundant naturally produced macromolecule on Earth. The enzymic degradation of cellulose, by cellulases, is therefore of great environmental and commercial significance. Cellulases are found in 12 of the glycoside hydrolase families classified according to their amino acid sequence similarities. Endoglucanase I (Cel7B), from the soft-rot fungus Humicola insolens, is a family 7 enzyme. The structure of the native form of Cel7B from H. insolens at 2.2 A resolution has been solved by molecular replacement using the known Trichoderma reesei cellobiohydrolase I [Divne, Ståhlberg, Reinikainen, Ruohonen, Pettersson, Knowles, Teeri and Jones (1994) Science 265, 524-528] structure as the search model. Cel7B catalyses hydrolysis of the beta-1,4 glycosidic linkages in cellulose with net retention of anomeric configuration. The catalytic nucleophile at the active site of Cel7B has been identified as Glu-197 by trapping of a 2-deoxy-2-fluorocellotriosyl enzyme intermediate and identification of the labelled peptide in peptic digests by tandem MS. Site-directed mutagenesis of both Glu-197 and the prospective catalytic acid, Glu-202, results in inactive enzyme, confirming the critical role of these groups for catalysis.

PubMed: 9761741

実験手法

X-RAY DIFFRACTION (2.2 Å)