Aerobic glycerol dissimilation via the Enterococcus faecalis DhaK pathway depends on NADH oxidase and a phosphotransfer reaction from PEP to DhaK via EIIADha

Microbiology (Reading). 2012 Oct;158(Pt 10):2661-2666. doi: 10.1099/mic.0.061663-0. Epub 2012 Aug 9.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters / genetics
  • ATP-Binding Cassette Transporters / metabolism
  • Aerobiosis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism
  • Dihydroxyacetone / metabolism
  • Enterococcus faecalis / genetics
  • Enterococcus faecalis / growth & development
  • Enterococcus faecalis / metabolism*
  • Gene Expression Regulation, Bacterial
  • Glycerol / metabolism*
  • Multienzyme Complexes / genetics
  • Multienzyme Complexes / metabolism*
  • NADH, NADPH Oxidoreductases / genetics
  • NADH, NADPH Oxidoreductases / metabolism*
  • Operon
  • Phosphoenolpyruvate / metabolism*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*

Substances

  • ATP-Binding Cassette Transporters
  • Bacterial Proteins
  • GldA protein, bacteria
  • Multienzyme Complexes
  • Phosphoenolpyruvate
  • NADH oxidase
  • NADH, NADPH Oxidoreductases
  • Phosphotransferases (Alcohol Group Acceptor)
  • glycerone kinase
  • Dihydroxyacetone
  • Glycerol