6MOY
Crystal structure of the E257A mutant of BlMan5B in complex with GlcNAc (co-crystallization)
Summary for 6MOY
Entry DOI | 10.2210/pdb6moy/pdb |
Descriptor | BlMan5B, 2-acetamido-2-deoxy-beta-D-glucopyranose (3 entities in total) |
Functional Keywords | family gh5, subfamily 18, beta-mannosidase, hydrolase |
Biological source | Bifidobacterium longum (strain DJO10A) |
Total number of polymer chains | 2 |
Total formula weight | 99653.56 |
Authors | Lorizolla-Cordeiro, R.,Giuseppe, P.O.,Murakami, M.T. (deposition date: 2018-10-05, release date: 2019-01-30, Last modification date: 2024-03-13) |
Primary citation | 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 Cited by 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: 30641082DOI: 10.1016/j.jmb.2018.12.017 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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