Details

Autor(en) / Beteiligte

• Ladevèze, Simon
• Tarquis, Laurence
• Cecchini, Davide A.
• Bercovici, Juliette
• André, Isabelle
• Topham, Christopher M.
• Morel, Sandrine
• Laville, Elisabeth
• Monsan, Pierre
• Lombard, Vincent
• Henrissat, Bernard
• Potocki-Véronèse, Gabrielle

Titel

Role of Glycoside Phosphorylases in Mannose Foraging by Human Gut Bacteria

Ist Teil von

• The Journal of biological chemistry, 2013-11, Vol.288 (45), p.32370-32383

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2013

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• To metabolize both dietary fiber constituent carbohydrates and host glycans lining the intestinal epithelium, gut bacteria produce a wide range of carbohydrate-active enzymes, of which glycoside hydrolases are the main components. In this study, we describe the ability of phosphorylases to participate in the breakdown of human N-glycans, from an analysis of the substrate specificity of UhgbMP, a mannoside phosphorylase of the GH130 protein family discovered by functional metagenomics. UhgbMP is found to phosphorolyze β-d-Manp-1,4-β-d-GlcpNAc-1,4-d-GlcpNAc and is also a highly efficient enzyme to catalyze the synthesis of this precious N-glycan core oligosaccharide by reverse phosphorolysis. Analysis of sequence conservation within family GH130, mapped on a three-dimensional model of UhgbMP and supported by site-directed mutagenesis results, revealed two GH130 subfamilies and allowed the identification of key residues responsible for catalysis and substrate specificity. The analysis of the genomic context of 65 known GH130 sequences belonging to human gut bacteria indicates that the enzymes of the GH130_1 subfamily would be involved in mannan catabolism, whereas the enzymes belonging to the GH130_2 subfamily would rather work in synergy with glycoside hydrolases of the GH92 and GH18 families in the breakdown of N-glycans. The use of GH130 inhibitors as therapeutic agents or functional foods could thus be considered as an innovative strategy to inhibit N-glycan degradation, with the ultimate goal of protecting, or restoring, the epithelial barrier. Background: The relations between the gut microbiota, food, and host play a crucial role in human health. Results: Prevalent bacterial glycoside phosphorylases are able to break down dietary carbohydrates and the N-glycans lining the intestinal epithelium. Conclusion: GH130 enzymes are new targets to study interactions between host and gut microbes. Significance: Glycoside phosphorylases are key enzymes of host glycan catabolism by gut bacteria.