RadA, a MSCRAMM Adhesin of the Dominant Symbiote <i>Ruminococcus gnavus</i> E1, Binds Human Immunoglobulins and Intestinal Mucins

Adhesion to the digestive mucosa is considered a key factor for bacterial persistence within the gut. In this study, we show that <i>Ruminococcus gnavus</i> E1 can express the <i>radA</i> gene, which encodes an adhesin of the MSCRAMMs family, only when it colonizes the gut. T...

Full description

Saved in:
Bibliographic Details
Main Authors: Marc Maresca, Radia Alatou, Ange Pujol, Cendrine Nicoletti, Josette Perrier, Thierry Giardina, Gwenola Simon, Vincent Méjean, Michel Fons
Format: article
Language:EN
Published: MDPI AG 2021
Subjects:
Online Access:https://doaj.org/article/402272ee27af48f49faa015e90d9db36
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Adhesion to the digestive mucosa is considered a key factor for bacterial persistence within the gut. In this study, we show that <i>Ruminococcus gnavus</i> E1 can express the <i>radA</i> gene, which encodes an adhesin of the MSCRAMMs family, only when it colonizes the gut. The RadA N-terminal region contains an all-β bacterial Ig-like domain known to interact with collagens. We observed that it preferentially binds human immunoglobulins (IgA and IgG) and intestinal mucins. Using deglycosylated substrates, we also showed that the RadA N-terminal region recognizes two different types of motifs, the protein backbone of human IgG and the glycan structure of mucins. Finally, competition assays with lectins and free monosaccharides identified Galactose and N-Acetyl-Galactosamine motifs as specific targets for the binding of RadA to mucins and the surface of human epithelial cells.