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A BETA-GLUCOSIDASE FROM AN AGROBACTERIUM SP - STRUCTURE AND BIOCHEMISTRY

TitleA BETA-GLUCOSIDASE FROM AN AGROBACTERIUM SP - STRUCTURE AND BIOCHEMISTRY
Publication TypeJournal Article
Year of Publication1993
AuthorsTRIMBUR, D, WARREN, RAJ, Withers, SG
JournalACS SYMPOSIUM SERIES
Volume533
Pagination42-55
ISSN0097-6156
Abstract

The beta-glucosidase (Abg) from an Agrobacterium sp. is a homodimer of monomers of molecular weight 51, 192. It is a retaining enzyme catalysing glycoside hydrolysis by a double-displacement mechanism in which an enzymic nucleophile (Glu358) attacks the substrate forming a glucosyl-enzyme intermediate which is then hydrolysed releasing beta-glucose. Comparisons of properties of the wild-type enzyme and its Glu358Asp mutant indicate that the principal roles for Glu358 are transition state stabilization and formation of the glycosyl-enzyme covalent intermediate, but not substrate binding. Other critical residues for enzyme activity are Gly360 and Asp374 and all three of these amino acids are conserved in the enzymes of family BGA of beta-glucosidases.