A hallmark of Bacteroidetes is their remarkable capacity to harvest and metabolize all kinds of complex carbohydrates. This property depends on specialized molecular complexes that are assembled at their surface. The archetype of these complexes is the Starch Utilization System (Sus) of Bacteroides thetaiotaomicron. These complexes are encoded in genomic loci called Polysaccharide Utilisation Loci (PUL). The genome of our reference strain C. canimorsus 5 contains13 PUL and these encode more than half of all proteins exposed at the bacterial surface. We have discovered that PUL5 encodes the Glycoproteins Deglycosylation complex (Gpd) enabling the bacterium to harvest amino sugars from the surface of eukaryotic cells including phagocytes as well as from soluble serum proteins, such as IgG and transferrin. The system is essential during the human infection because it represents for C. canimorsus the only source of amino sugars necessary for the synthesis of their peptidoglycan. We also discovered that PUL3 encodes a novel iron acquisition system allowing the bacterium to fetch iron from human transferrin. Finally, PUL9 encodes the Muc complex, devoted to mucin degradation, an abundant carbohydrate source for C. canimorsus in its ecological niche, the dog’s mouth.
Main publications:
- Renzi F., Manfredi P., Dol M., Fu J., Vincent S., Cornelis G.R. Glycan-foraging systems reveal the adaptation of Capnocytophaga canimorsus to the dog mouth. MBio. 2015 Mar 3;6(2):e02507. doi: 10.1128/mBio.02507-14.
- Manfredi, P., Lauber, F., Renzi, F., Hack, K., Hess, E. & Cornelis, G. R. New iron acquisition system in Bacteroidetes. Infection and Immunity. 83, 1, p. 300-310 11 p.
- Manfredi P., Renzi F., Mally M., Sauteur L., Schmaler M., Moes S., Jenö P., Cornelis G.R. The genome and surface proteome of Capnocytophaga canimorsus reveal a key role of glycan foraging systems in host glycoproteins deglycosylation. Mol Microbiol. 2011 Aug;81(4):1050-60. doi:10.1111/j.1365-2958.2011.07750.x.
- Renzi F., Manfredi P., Mally M., Moes S., Jenö P., Cornelis G.R. The N-glycan Glycoprotein Deglycosylation Complex (Gpd) from Capnocytophaga canimorsus Deglycosylates Human IgG. PLoS Pathog. 2011 Jun;7(6):e1002118.
- Mally M., Shin H., Paroz C., Landmann R., Cornelis G.R.: Capnocytophaga canimorsus: a human pathogen feeding at the surface of epithelial cells and phagocytes. PloS Pathog. 2008 Sep 26;4(9):e1000164. doi: 10.1371/journal.ppat.1000164.
