2A3H

CELLOBIOSE COMPLEX OF THE ENDOGLUCANASE CEL5A FROM BACILLUS AGARADHERANS AT 2.0 A RESOLUTION

Summary for 2A3H

• Entry DOI: 10.2210/pdb2a3h/pdb
• Related PRD ID: PRD_900005
• Descriptor: ENDOGLUCANASE, beta-D-glucopyranose-(1-4)-beta-D-glucopyranose (3 entities in total)
• Functional Keywords: endoglucanase, cellulose degradation, glycoside hydrolase family 5
• Biological source: Bacillus agaradhaerens
• Total number of polymer chains: 1
• Total formula weight: 33996.04

Authors

Davies, G.J.,Brzozowski, A.M.,Andersen, K.,Schulein, M. (deposition date: 1998-01-22, release date: 1999-03-16, Last modification date: 2024-02-14)

Primary citation

Davies, G.J.,Dauter, M.,Brzozowski, A.M.,Bjornvad, M.E.,Andersen, K.V.,Schulein, M.
Structure of the Bacillus agaradherans family 5 endoglucanase at 1.6 A and its cellobiose complex at 2.0 A resolution
Biochemistry, 37:1926-1932, 1998

PubMed Abstract: The enzymatic degradation of cellulose, by cellulases, is not only industrially important in the food, paper, and textile industries but also a potentially useful method for the environmentally friendly recycling of municipal waste. An understanding of the structural and mechanistic requirements for the hydrolysis of the beta-1,4 glycosidic bonds of cellulose is an essential prerequisite for beneficial engineering of cellulases for these processes. Cellulases have been classified into 13 of the 62 glycoside hydrolase families [Henrissat, B., and Bairoch, A. (1996) Biochem J. 316, 695-696]. The structure of the catalytic core of the family 5 endoglucanase, Ce15A, from the alkalophilic Bacillus agaradherans has been solved by multiple isomorphous replacement at 1.6 A resolution. Ce15A has the (alpha/beta)8 barrel structure and signature structural features typical of the grouping of glycoside hydrolase families known as clan GH-A, with the catalytic acid/base Glu 139 and nucleophile Glu 228 on barrel strands beta 4 and beta 7 as expected. In addition to the native enzyme, the 2.0 A resolution structure of the cellobiose-bound form of the enzyme has also been determined. Cellobiose binds preferentially in the -2 and -3 subsites of the enzyme. Kinetic studies on the isolated catalytic core domain of Ce15A, using a series of reduced cellodextrins as substrates, suggest approximately five to six binding sites, consistent with the shape and size of the cleft observed by crystallography.

PubMed: 9485319
DOI: 10.1021/bi972162m

Experimental method

X-RAY DIFFRACTION (2 Å)