title: Aerobic glycerol dissimilation via the Enterococcus faecalis DhaK pathway depends on NADH oxidase and a phosphotransfer reaction from PEP to DhaK via EIIADha.
abstract: Two pathways for glycerol dissimilation are present in Enterococcus faecalis. Either glycerol is first phosphorylated by glycerol kinase and then oxidized by glycerol-3-phosphate oxidase with molecular oxygen as the electron acceptor (GlpO/GlpK pathway), or it is first oxidized by glycerol dehydrogenase with NAD(+) as the acceptor of the reduction equivalents and then phosphorylated by dihydroxyacetone kinase (GldA/DhaK pathway). The final end product in both cases is dihydroxyacetone phosphate (DHAP). The genes of the GldA/DhaK pathway are present in a four-gene operon structure encoding GldA, a small hypothetical protein (EF1359), and two subunits of dihydroxyacetone kinase (DhaK and DhaL). We demonstrate in this study that protein EF1359 is part of a phosphorylation cascade which phosphorylates dihydroxyacetone in a phosphoenolpyruvate (PEP)-dependent reaction via EI, HPr, EF1359 and DhaLK. Furthermore we show that aerobic dissimilation of glycerol via the GldA/DhaK pathway is dependent on active NADH oxidase to regenerate NADH in Ent. faecalis. A refined model of the aerobic metabolism of glycerol via the GldA/DhaK pathway is presented.
authors.affiliation: Université de Caen Basse-Normandie, EA4655 U2RM-Stress and Virulence, F-14032 Caen, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Sauvageot
authors.affiliation: Université de Caen Basse-Normandie, EA4655 U2RM-Stress and Virulence, F-14032 Caen, France.
authors.forename: Rabia
authors.initials: R
authors.lastname: Ladjouzi
authors.affiliation: Université de Caen Basse-Normandie, EA4655 U2RM-Stress and Virulence, F-14032 Caen, France.
authors.forename: Abdellah
authors.initials: A
authors.lastname: Benachour
authors.affiliation: Université de Caen Basse-Normandie, EA4655 U2RM-Stress and Virulence, F-14032 Caen, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Rincé
authors.affiliation: Centre National de la Recherche Scientifique, SNC9130 Micalis, F-78350 Jouy-en-Josas, France.|AgroParisTech, UMR Micalis, F-78350 Jouy-en-Josas, France.|Institut de la Recherche Agronomique, UMR1319 Micalis, F-78350 Jouy-en-Josas, France.
authors.forename: Josef
authors.initials: J
authors.lastname: Deutscher
authors.affiliation: Université de Caen Basse-Normandie, EA4655 U2RM-Stress and Virulence, F-14032 Caen, France.
authors.forename: Axel
authors.initials: A
authors.lastname: Hartke
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000235:genetics / Q000378:metabolism; D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D004098:Dihydroxyacetone / Q000378:metabolism; D013293:Enterococcus faecalis / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005990:Glycerol / Q000378:metabolism*; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D009876:Operon; D010728:Phosphoenolpyruvate / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*
chemical_list: D018528:ATP-Binding Cassette Transporters; D001426:Bacterial Proteins; C109038:GldA protein, bacteria; D009097:Multienzyme Complexes; D010728:Phosphoenolpyruvate; C023107:NADH oxidase; D009247:NADH, NADPH Oxidoreductases; D017853:Phosphotransferases (Alcohol Group Acceptor); C023132:glycerone kinase; D004098:Dihydroxyacetone; D005990:Glycerol