6MPC

Crystal structure of E257A mutant of BlMan5B

6MPC の概要

• エントリーDOI: 10.2210/pdb6mpc/pdb
• 分子名称: BlMan5B (2 entities in total)
• 機能のキーワード: family gh5, subfamily 18, beta-mannosidase, hydrolase
• 由来する生物種: Bifidobacterium longum (strain DJO10A)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 99211.15

構造登録者

Lorizolla-Cordeiro, R.,Giuseppe, P.O.,Murakami, M.T. (登録日: 2018-10-05, 公開日: 2019-01-30, 最終更新日: 2024-03-13)

主引用文献

Cordeiro, R.L.,Pirolla, R.A.S.,Persinoti, G.F.,Gozzo, F.C.,de Giuseppe, P.O.,Murakami, M.T.
N-glycan Utilization by Bifidobacterium Gut Symbionts Involves a Specialist beta-Mannosidase.
J. Mol. Biol., 431:732-747, 2019

PubMed Abstract: Bifidobacteria represent one of the first colonizers of human gut microbiota, providing to this ecosystem better health and nutrition. To maintain a mutualistic relationship, they have enzymes to degrade and use complex carbohydrates non-digestible by their hosts. To succeed in the densely populated gut environment, they evolved molecular strategies that remain poorly understood. Herein, we report a novel mechanism found in probiotic Bifidobacteria for the depolymerization of the ubiquitous 2-acetamido-2-deoxy-4-O-(β-d-mannopyranosyl)-d-glucopyranose (Man-β-1,4-GlcNAc), a disaccharide that composes the universal core of eukaryotic N-glycans. In contrast to Bacteroidetes, these Bifidobacteria have a specialist and strain-specific β-mannosidase that contains three distinctive structural elements conferring high selectivity for Man-β-1,4-GlcNAc: a lid that undergoes conformational changes upon substrate binding, a tryptophan residue swapped between the two dimeric subunits to accommodate the GlcNAc moiety, and a Rossmann fold subdomain strategically located near to the active site pocket. These key structural elements for Man-β-1,4-GlcNAc specificity are highly conserved in Bifidobacterium species adapted to the gut of a wide range of social animals, including bee, pig, rabbit, and human. Together, our findings uncover an unprecedented molecular strategy employed by Bifidobacteria to selectively uptake carbohydrates from N-glycans in social hosts.

PubMed: 30641082
DOI: 10.1016/j.jmb.2018.12.017

実験手法

X-RAY DIFFRACTION (1.8 Å)