The role of the oligosaccharide binding cleft of rice BGlu1 in hydrolysis of cellooligosaccharides and in their synthesis by rice BGlu1 glycosynthase.

ABSTRACT: Rice BGlu1 β-glucosidase nucleophile mutant E386G is a glycosynthase that can synthesize p-nitrophenyl (pNP)-cellooligosaccharides of up to 11 residues. The X-ray crystal structures of the E386G glycosynthase with and without α-glucosyl fluoride were solved and the α-glucosyl fluoride complex was found to contain an ordered water molecule near the position of the nucleophile of the BGlu1 native structure, which is likely to stabilize the departing fluoride. The structures of E386G glycosynthase in complexes with cellotetraose and cellopentaose confirmed that the side chains of N245, S334, and Y341 interact with glucosyl residues in cellooligosaccharide binding subsites +2, +3, and +4. Mutants in which these residues were replaced in BGlu1 β-glucosidase hydrolyzed cellotetraose and cellopen

SUBMITTER: Pengthaisong S 

PROVIDER: S-EPMC3375437 | biostudies-literature | 2012 Mar

REPOSITORIES: biostudies-literature