Extracellular vesicle-linked vitamin B12 acquisition via novel binding proteins in Bacteroides thetaiotaomicron.

ABSTRACT: Vitamin B12 (cobalamin) and related cobamides are essential cofactors for many gut bacteria, yet their acquisition requires complex uptake systems due to limited availability. In the human gut commensal Bacteroides thetaiotaomicron, cobamide uptake is mediated by multiple operons encoding outer membrane proteins, transporters and uncharacterised lipoproteins, some of which are incorporated into bacterial extracellular vesicles (BEVs). Here, we advance the functional and structural understanding of this cobamide acquisition system by examining previously uncharacterised features. Bioinformatic and promoter-reporter analyses revealed four uptake operons, including novel genes we designate btuK, btuJ, btuL and btuX, with evidence for internal promoters and riboswitch regulation. Recombinant e

SUBMITTER: Juodeikis R 

PROVIDER: S-EPMC12751083 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature