1. Discovery of intramolecular trans-sialidases in human gut microbiota suggests novel mechanisms of mucosal adaptation
- Author
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John Walshaw, Nathalie Juge, Willem M. de Vos, C. David Owen, Gwénaëlle Le Gall, Garry L. Taylor, Louise E. Tailford, Emmanuelle H. Crost, Jemma Hardy-Goddard, University of St Andrews. School of Biology, University of St Andrews. Office of the Principal, University of St Andrews. Biomedical Sciences Research Complex, Departments of Faculty of Veterinary Medicine, Willem Meindert Vos de / Principal Investigator, Veterinary Biosciences, Department of Bacteriology and Immunology, Medicum, and de Vos & Salonen group
- Subjects
MUCIN ,General Physics and Astronomy ,STREPTOCOCCUS-PNEUMONIAE ,Gut flora ,Entric pathogens ,chemistry.chemical_compound ,Intestinal mucosa ,Ruminococcus gnavus ,Microbiologie ,INFLAMMATORY BOWEL DISEASES ,Ruminococcus ,CRYSTAL-STRUCTURE ,Intestinal Mucosa ,SPECIFICITY ,R2C ,2. Zero hunger ,Gastrointestinal tract ,Multidisciplinary ,Streptococcus-pneumoniae ,Adaptation, Physiological ,Biochemistry ,Crystal-structure ,BACTERIA ,Specificity ,BDC ,Neuraminidase ,Inflammatory bowel-diseases ,Sialic-acid ,MUCUS LAYERS ,Biology ,METABOLISM ,R Medicine ,Sialidase ,Microbiology ,General Biochemistry, Genetics and Molecular Biology ,Gene Expression Regulation, Enzymologic ,Article ,SDG 3 - Good Health and Well-being ,Life Science ,Humans ,SIALIC-ACID ,VLAG ,Glycoproteins ,Bacteria ,Mucin ,Mucins ,General Chemistry ,Gene Expression Regulation, Bacterial ,biology.organism_classification ,Sialic acid ,Mucus layers ,Metabolism ,chemistry ,3111 Biomedicine ,ENTERIC PATHOGENS - 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., Mucosal sialoglycans contribute to host–microbe interactions at mucosal surfaces and impact bacterial colonization of the digestive system. Here the authors identify and characterize an intramolecular trans-sialidase produced by the gut bacterium R. gnavus ATCC 29149 that may contribute to adaptation to the mucosal environment.
- Published
- 2015