Substrate preference of an ABC importer corresponds to selective growth on β-(1,6)-galactosides in Bifidobacterium animalis subsp. lactis.

ABSTRACT: Bifidobacteria are exposed to substantial amounts of dietary β-galactosides. Distinctive preferences for growth on different β-galactosides are observed within Bifidobacterium members, but the basis of these preferences remains unclear. We previously described the first β-(1,6)/(1,3)-galactosidase from Bifidobacterium animalis subsp. lactis Bl-04. This enzyme is relatively promiscuous, exhibiting only 5-fold higher efficiency on the preferred β-(1,6)-galactobiose than the β-(1,4) isomer. Here, we characterize the solute-binding protein (Bal6GBP) that governs the specificity of the ABC transporter encoded by the same β-galactoside utilization locus. We observed that although Bal6GBP recognizes both β-(1,6)- and β-(1,4)-galactobiose, Bal6GBP has a 16

SUBMITTER: Theilmann MC 

PROVIDER: S-EPMC6682729 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature