7BIZ

Structure of a B12 binding lipoprotein from Bacteroides thetaiotaomicron

Summary for 7BIZ

• Entry DOI: 10.2210/pdb7biz/pdb
• Descriptor: Cell surface protein, CYANOCOBALAMIN, CALCIUM ION, ... (7 entities in total)
• Functional Keywords: b12 binding protein, lipoprotein, unknown function
• Biological source: Bacteroides thetaiotaomicron
• Total number of polymer chains: 2
• Total formula weight: 120012.85

Authors

Abellon-Ruiz, J.,van den Berg, B. (deposition date: 2021-01-13, release date: 2022-03-02, Last modification date: 2024-05-01)

Primary citation

Putnam, E.E.,Abellon-Ruiz, J.,Killinger, B.J.,Rosnow, J.J.,Wexler, A.G.,Folta-Stogniew, E.,Wright, A.T.,van den Berg, B.,Goodman, A.L.
Gut Commensal Bacteroidetes Encode a Novel Class of Vitamin B 12 -Binding Proteins.
Mbio, 13:e0284521-e0284521, 2022

PubMed Abstract: Human gut commensal rely on multiple transport systems to acquire vitamin B and related cobamides for fitness in the gut. In addition to a set of conserved transport proteins, these systems also include a diverse repertoire of additional proteins with unknown function. Here, we report the function and structural characterization of one of these proteins, BtuH, which binds vitamin B directly via a C-terminal globular domain that has no known structural homologs. This protein is required for efficient B transport and competitive fitness in the gut, demonstrating that members of the heterogeneous suite of accessory proteins encoded in cobamide transport system loci can play key roles in vitamin acquisition. The gut microbiome is a complex microbial community with important impacts on human health. One of the major groups within the gut microbiome, the , rely on their ability to capture vitamin B and related molecules for fitness in the gut. Unlike well-studied model organisms, gut genomes often include multiple vitamin B transport systems with a heterogeneous set of components. The role, if any, of these components was unknown. Here, we identify new proteins that play key roles in vitamin B capture in these organisms. Notably, these proteins are associated with some B transport systems and not others (even in the same bacterial strain), suggesting that these systems may assemble into functionally distinct machines to capture vitamin B and related molecules.

PubMed: 35227073
DOI: 10.1128/mbio.02845-21

Experimental method

X-RAY DIFFRACTION (1.53 Å)