Sucrose 6F-phosphate phosphorylase: a novel insight in the human gut microbiome
2019
Tauzin, Alexandra | Bruel, Laetitia | Laville, Elisabeth | Nicoletti, Cendrine | Navarro, David | Henrissat, Bernard | Perrier, Josette | Potocki-Veronese, Gabrielle | Giardina, Thierry | Lafond, Mickael | Laboratoire d'Ingénierie des Systèmes Biologiques et des Procédés (LISBP) ; Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse) ; Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS) | Institut des Sciences Moléculaires de Marseille (ISM2) ; Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | Centre National de la Recherche Scientifique (CNRS) | École Centrale de Marseille (ECM) | Biodiversité et Biotechnologie Fongiques (BBF) ; Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM) | Architecture et fonction des macromolécules biologiques (AFMB) ; Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS) | Department of Biological Sciences ; University of Nevada [Reno]
The human gut microbiome plays an essential role in maintaining human health including in degradation of dietary fibres and carbohydrates further used as nutrients by both the host and the gut bacteria. Previously, we identified a polysaccharide utilization loci (PUL) involved in sucrose and raffinose family oligosaccharide (RFO) metabolism from one of the most common Firmicutes present in individuals, Ruminococcus gnavus E1. One of the enzymes encoded by this PUL was annotated as a putative sucrose phosphate phosphorylase (RgSPP). In the present study, we have in-depth characterized the heterologously expressed RgSPP as sucrose 6F-phosphate phosphorylase (SPP), expanding our knowledge of the glycoside hydrolase GH13_18 subfamily. Specifically, the enzymatic characterization showed a selective activity on sucrose 6F-phosphate (S6FP) acting both in phosphorolysis releasing alpha-d-glucose-1-phosphate (G1P) and alpha-d-fructose-6-phosphate (F6P), and in reverse phosphorolysis from G1P and F6P to S6FP. Interestingly, such a SPP activity had never been observed in gut bacteria before. In addition, a phylogenetic and synteny analysis showed a clustering and a strictly conserved PUL organization specific to gut bacteria. However, a wide prevalence and abundance study with a human metagenomic library showed a correlation between SPP activity and the geographical origin of the individuals and, thus, most likely linked to diet. Rgspp gene overexpression has been observed in mice fed with a high-fat diet suggesting, as observed for humans, that intestine lipid and carbohydrate microbial metabolisms are intertwined. Finally, based on the genomic environment analysis, in vitro and in vivo studies, results provide new insights into the gut microbiota catabolism of sucrose, RFOs and S6FP.
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