1cem

ENDOGLUCANASE A (CELA) CATALYTIC CORE, RESIDUES 33-395

spinqualitylabelsall models 1cem, resolution 1.65Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1cem is a 1 chain structure with sequence from Atcc 27405. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Gene: CELA (ATCC 27405) Activity: Cellulase, with EC number 3.2.1.4 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum Function [GUNA_CLOTM] This enzyme catalyzes the endohydrolysis of 1,4-beta-glucosidic linkages in cellulose, lichenin and cereal beta-D-glucans. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed BACKGROUND. Cellulases, which catalyze the hydrolysis of glycosidic bonds in cellulose, can be classified into several different protein families. Endoglucanase CelA is a member of glycosyl hydrolase family 8, a family for which no structural information was previously available. RESULTS. The crystal structure of CelA was determined by multiple isomorphous replacement and refined to 1.65 A resolution. The protein folds into a regular (alpha/alpha)6 barrel formed by six inner and six outer alpha helices. Cello-oligosaccharides bind to an acidic cleft containing at least five D-glucosyl-binding subsites (A-E) such that the scissile glycosidic linkage lies between subsites C and D. The strictly conserved residue Glu95, which occupies the center of the substrate-binding cleft and is hydrogen bonded to the glycosidic oxygen, has been assigned the catalytic role of proton donor. CONCLUSIONS. The present analysis provides a basis for modeling homologous family 8 cellulases. The architecture of the active-site cleft, presenting at least five glucosyl-binding subsites, explains why family 8 cellulases cleave cello-oligosaccharide polymers that are at least five D-glycosyl subunits long. Furthermore, the structure of CelA allows comparison with (alpha/alpha)6 barrel glycosidases that are not related in sequence, suggesting a possible, albeit distant, evolutionary relationship between different families of glycosyl hydrolases. The crystal structure of endoglucanase CelA, a family 8 glycosyl hydrolase from Clostridium thermocellum.,Alzari PM, Souchon H, Dominguez R Structure. 1996 Mar 15;4(3):265-75. PMID:8805535 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Glucanase

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