4X6K

Crystal structure of the intramolecular trans-sialidase from Ruminococcus gnavus in complex with Siastatin B

Summary for 4X6K

• Entry DOI: 10.2210/pdb4x6k/pdb
• Descriptor: Anhydrosialidase, ACETYL GROUP, (2S,3R,4S,5S)-2-(acetylamino)-5-carboxy-3,4-dihydroxypiperidinium, ... (4 entities in total)
• Functional Keywords: intramolecular, trans-sialidase, sialidase, neuraminidase, siastatin b, inhibitor, complex, hydrolase, anhydrosialidase
• Biological source: Ruminococcus gnavus CC55_001C
• Total number of polymer chains: 1
• Total formula weight: 53996.55

Authors

Owen, C.D.,Tailford, L.E.,Taylor, G.L.,Juge, N. (deposition date: 2014-12-08, release date: 2015-07-22, Last modification date: 2024-01-10)

Primary citation

Tailford, L.E.,Owen, C.D.,Walshaw, J.,Crost, E.H.,Hardy-Goddard, J.,Le Gall, G.,de Vos, W.M.,Taylor, G.L.,Juge, N.
Discovery of intramolecular trans-sialidases in human gut microbiota suggests novel mechanisms of mucosal adaptation.
Nat Commun, 6:7624-7624, 2015

PubMed Abstract: The gastrointestinal mucus layer is colonized by a dense community of microbes catabolizing dietary and host carbohydrates during their expansion in the gut. Alterations in mucosal carbohydrate availability impact on the composition of microbial species. Ruminococcus gnavus is a commensal anaerobe present in the gastrointestinal tract of >90% of humans and overrepresented in inflammatory bowel diseases (IBD). Using a combination of genomics, enzymology and crystallography, we show that the mucin-degrader R. gnavus ATCC 29149 strain produces an intramolecular trans-sialidase (IT-sialidase) that cleaves off terminal α2-3-linked sialic acid from glycoproteins, releasing 2,7-anhydro-Neu5Ac instead of sialic acid. Evidence of IT-sialidases in human metagenomes indicates that this enzyme occurs in healthy subjects but is more prevalent in IBD metagenomes. Our results uncover a previously unrecognized enzymatic activity in the gut microbiota, which may contribute to the adaptation of intestinal bacteria to the mucosal environment in health and disease.

PubMed: 26154892
DOI: 10.1038/ncomms8624

Experimental method

X-RAY DIFFRACTION (1.94 Å)