A ?-mannan utilization locus in Bacteroides ovatus involves a GH36 ?-galactosidase active on galactomannans.

ABSTRACT: The Bacova_02091 gene in the ?-mannan utilization locus of Bacteroides ovatus encodes a family GH36 ?-galactosidase (BoGal36A), transcriptionally upregulated during growth on galactomannan. Characterization of recombinant BoGal36A reveals unique properties compared to other GH36 ?-galactosidases, which preferentially hydrolyse terminal ?-galactose in raffinose family oligosaccharides. BoGal36A prefers hydrolysing internal galactose substitutions from intact and depolymerized galactomannan. BoGal36A efficiently releases (> 90%) galactose from guar and locust bean galactomannans, resulting in precipitation of the polysaccharides. As compared to other GH36 structures, the BoGal36A 3D model displays a loop deletion, resulting in a wider active site cleft which likely can accommodate a galactose-substituted polymannose backbone.

SUBMITTER: Reddy SK 

PROVIDER: S-EPMC5094572 | biostudies-literature | 2016 Jul

REPOSITORIES: biostudies-literature