Biochemistry & Analytical Biochemistry

How sweet are our gut beneficial microbes?

Global Congress on Biochemistry, Glycomics & Amino Acids

December 08-09, 2016 San Antonio, USA

Dimitris Latousakis, Donald A MacKenzie, Devon Kavanaugh, Karine Lecointe, Robert A Field and Nathalie Juge

Institute of Food Research, UK
John Innes Centre, UK

Posters & Accepted Abstracts: Biochem Anal Biochem

Abstract:

Glycosylation is the most common post translational modification of proteins in nature and is essential to various biological and physical processes. Protein glycosylation in prokaryotes and especially pathogens has attracted much attention in recent years due to its role in adhesion, colonisation or virulence. In contrast, and despite the increasing interest in gut microbiota, not much is known on protein glycosylation in commensal bacteria. Adhesion of gut commensals to the host tissue is the first step to successful colonisation and is mediated by bacterial surface proteins called adhesins. Recent studies established Lactobacillus reuteri as a model organism to study the evolution and host specialisation of gut symbionts. L. reuteri colonises the gut of various vertebrates and expresses cell-surface adhesins mediating the interaction of the strains to their specific host. Using a combination of lectin affinity studies, gas chromatography and mass spectrometry (MALDI-ToF, ESI-MS), we have obtained evidence that the main L. reuteri adhesins are glycosylated. These include mucus-binding proteins from human and pig strains, serine-richrepeat proteins (SRRs) from pig and rodent isolates and muramidase from human strains. Our preliminary data suggest that L. reuteri glycosylates proteins using short, neutral glycan chains. We are also investigating by mutagenesis the molecular pathways leading to SRR glycosylation via the acceessory secretion system (SecA2/Y2) gene cluster. Taken together our data suggest that the L. reuteri SecA2/Y2 cluster is dedicated to the glycosylation of SRRs, and there is at least one additional glycosylation system responsible for the glycosylation of other adhesins.

Biography :

Email: Dimitris.Latousakis@ifr.ac.uk