7KWB

Surface glycan-binding protein B from Bacteroides thetaiotaomicron

7KWB の概要

• エントリーDOI: 10.2210/pdb7kwb/pdb
• 分子名称: BtSGBP-B (2 entities in total)
• 機能のキーワード: cbm, sugar binding protein, lectin
• 由来する生物種: Bacteroides thetaiotaomicron
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 101504.76

構造登録者

Tamura, K.,Brumer, H.,Van Petegem, F. (登録日: 2020-11-30, 公開日: 2021-02-17, 最終更新日: 2024-03-06)

主引用文献

Tamura, K.,Dejean, G.,Van Petegem, F.,Brumer, H.
Distinct protein architectures mediate species-specific beta-glucan binding and metabolism in the human gut microbiota.
J.Biol.Chem., 296:100415-100415, 2021

PubMed Abstract: Complex glycans that evade our digestive system are major nutrients that feed the human gut microbiota (HGM). The prevalence of Bacteroidetes in the HGM of populations worldwide is engendered by the evolution of polysaccharide utilization loci (PULs), which encode concerted protein systems to utilize the myriad complex glycans in our diets. Despite their crucial roles in glycan recognition and transport, cell-surface glycan-binding proteins (SGBPs) remained understudied cogs in the PUL machinery. Here, we report the structural and biochemical characterization of a suite of SGBP-A and SGBP-B structures from three syntenic β(1,3)-glucan utilization loci (1,3GULs) from Bacteroides thetaiotaomicron (Bt), Bacteroides uniformis (Bu), and B. fluxus (Bf), which have varying specificities for distinct β-glucans. Ligand complexes provide definitive insight into β(1,3)-glucan selectivity in the HGM, including structural features enabling dual β(1,3)-glucan/mixed-linkage β(1,3)/β(1,4)-glucan-binding capability in some orthologs. The tertiary structural conservation of SusD-like SGBPs-A is juxtaposed with the diverse architectures and binding modes of the SGBPs-B. Specifically, the structures of the trimodular BtSGBP-B and BuSGBP-B revealed a tandem repeat of carbohydrate-binding module-like domains connected by long linkers. In contrast, BfSGBP-B comprises a bimodular architecture with a distinct β-barrel domain at the C terminus that bears a shallow binding canyon. The molecular insights obtained here contribute to our fundamental understanding of HGM function, which in turn may inform tailored microbial intervention therapies.

PubMed: 33587952
DOI: 10.1016/j.jbc.2021.100415

実験手法

X-RAY DIFFRACTION (2.6 Å)