The human gut symbiont Ruminococcus gnavus shows specificity to blood group A antigen during mucin glycan foraging: Implication for niche colonisation in the gastrointestinal tract

Wu, Haiyang, Crost, Emmanuelle H., Owen, C. David, Van Bakel, Wouter, Martínez Gascueña, Ana, Latousakis, Dimitrios, Hicks, Thomas, Walpole, Samuel, Urbanowicz, Paulina A., Ndeh, Didier, Monaco, Serena, Sánchez Salom, Laura, Griffiths, Ryan, Reynolds, Raven S., Colvile, Anna, Spencer, Daniel I. R., Walsh, Martin, Angulo, Jesus and Juge, Nathalie (2021) The human gut symbiont Ruminococcus gnavus shows specificity to blood group A antigen during mucin glycan foraging: Implication for niche colonisation in the gastrointestinal tract. PLoS Biology, 19 (12). ISSN 1545-7885

[img]
Preview
PDF (Proof)
Available under License Creative Commons Attribution.

Download (6MB) | Preview

Abstract

AU The:human Pleaseconfirmthatallheadinglevelsarerepresentedcorrectly gut symbiont Ruminococcus gnavus displays strain-specific : repertoires of glycoside hydrolases (GHs) contributing to its spatial location in the gut. Sequence similarity network analysis identified strain-specific differences in blood-group endo-β-1,4-galactosidase belonging to the GH98 family. We determined the substrate and linkage specificities of GH98 from R. gnavus ATCC 29149, RgGH98, against a range of defined oligosaccharides and glycoconjugates including mucin. We showed by HPAEC-PAD and LC-FD-MS/MS that RgGH98 is specific for blood group A tetrasaccharide type II (BgA II). Isothermal titration calorimetry (ITC) and saturation transfer difference (STD) NMR confirmed RgGH98 affinity for blood group A over blood group B and H antigens. The molecular basis of RgGH98 strict specificity was further investigated using a combination of glycan microarrays, site-directed mutagenesis, and X-ray crystallography. The crystal structures of RgGH98 in complex with BgA trisaccharide (BgAtri) and of RgGH98 E411A with BgA II revealed a dedicated hydrogen network of residues, which were shown by site-directed mutagenesis to be critical to the recognition of the BgA epitope. We demonstrated experimentally that RgGH98 is part of an operon of 10 genes that is overexpresssed in vitro when R. gnavus ATCC 29149 is grown on mucin as sole carbon source as shown by RNAseq analysis and RT-qPCR confirmed RgGH98 expression on BgA II growth. Using MALDI-ToF MS, we showed that RgGH98 releases BgAtri from mucin and that pretreatment of mucin with RgGH98 confered R. gnavus E1 the ability to grow, by enabling the E1 strain to metabolise BgAtri and access the underlying mucin glycan chain. These data further support that the GH repertoire of R. gnavus strains enable them to colonise different nutritional niches in the human gut and has potential applications in diagnostic and therapeutics against infection.

Item Type: Article
Uncontrolled Keywords: neuroscience(all),biochemistry, genetics and molecular biology(all),immunology and microbiology(all),agricultural and biological sciences(all) ,/dk/atira/pure/subjectarea/asjc/2800
Faculty \ School: Faculty of Medicine and Health Sciences > Norwich Medical School
Faculty of Science > School of Biological Sciences
Faculty of Science > School of Chemistry
Faculty of Science > School of Pharmacy
Faculty of Science
Related URLs:
Depositing User: LivePure Connector
Date Deposited: 23 Dec 2021 14:30
Last Modified: 17 Jan 2022 10:30
URI: https://ueaeprints.uea.ac.uk/id/eprint/82812
DOI: 10.1371/journal.pbio.3001498

Actions (login required)

View Item View Item