A Bacteroidetes locus dedicated to fungal 1,6-β-glucan degradation: Unique substrate conformation drives specificity of the key endo-1,6-β-glucanase.

ABSTRACT: Glycans are major nutrients available to the human gut microbiota. The Bacteroides are generalist glycan degraders, and this function is mediated largely by polysaccharide utilization loci (PULs). The genomes of several Bacteroides species contain a PUL, PUL_{1,6-β-glucan}, that was predicted to target mixed linked plant 1,3;1,4-β-glucans. To test this hypothesis we characterized the proteins encoded by this locus in Bacteroides thetaiotaomicron, a member of the human gut microbiota. We show here that PUL_{1,6-β-glucan} does not orchestrate the degradation of a plant polysaccharide but targets a fungal cell wall glycan, 1,6-β-glucan, which is a growth substrate for the bacterium. The locus is up-regulated by 1,6-β-glucan and encodes two enzymes, a surfa

SUBMITTER: Temple MJ 

PROVIDER: S-EPMC5481569 | biostudies-literature | 2017 Jun

REPOSITORIES: biostudies-literature