1edg
From Proteopedia
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SINGLE CRYSTAL STRUCTURE DETERMINATION OF THE CATALYTIC DOMAIN OF CELCCA CARRIED OUT AT 15 DEGREE C
Overview
BACKGROUND: Cellulases are glycosyl hydrolases--enzymes that hydrolyze glycosidic bonds. They have been widely studied using biochemical and microbiological techniques and have attracted industrial interest because of their potential in biomass conversion and in the paper and textile industries. Glycosyl hydrolases have lately been assigned to specific families on the basis of similarities in their amino acid sequences. The cellulase endoglucanase A produced by Clostridium cellulolyticum (CelCCA) belongs to family 5. RESULTS: We have determined the crystal structure of the catalytic domain of CelCCA at a resolution of 2.4 A and refined it to 1.6 A. The structure was solved by the multiple isomorphous replacement method. The overall structural fold, (alpha/beta)8, belongs to the TIM barrel motif superfamily. The catalytic centre is located at the C-terminal ends of the beta strands; the aromatic residues, forming the substrate-binding site, are arranged along a long cleft on the surface of the globular enzyme. CONCLUSIONS: Strictly conserved residues within family 5 are described with respect to their catalytic function. The proton donor, Glu170, and the nucleophile, Glu307, are localized on beta strands IV and VII, respectively, and are separated by 5.5 A, as expected for enzymes which retain the configuration of the substrate's anomeric carbon. Structure determination of the catalytic domain of CelCCA allows a comparison with related enzymes belonging to glycosyl hydrolase families 2, 10 and 17, which also display an (alpha/beta)8 fold.
About this Structure
1EDG is a Single protein structure of sequence from Clostridium cellulolyticum. Active as Cellulase, with EC number 3.2.1.4 Full crystallographic information is available from OCA.
Reference
Crystal structure of the catalytic domain of a bacterial cellulase belonging to family 5., Ducros V, Czjzek M, Belaich A, Gaudin C, Fierobe HP, Belaich JP, Davies GJ, Haser R, Structure. 1995 Sep 15;3(9):939-49. PMID:8535787
Page seeded by OCA on Thu Feb 21 12:26:33 2008
