Novel listerial glycerol dehydrogenase- and phosphoenolpyruvate-dependent dihydroxyacetone kinase system connected to the pentose phosphate pathway

J Bacteriol. 2012 Sep;194(18):4972-82. doi: 10.1128/JB.00801-12. Epub 2012 Jul 6.

Abstract

Several bacteria use glycerol dehydrogenase to transform glycerol into dihydroxyacetone (Dha). Dha is subsequently converted into Dha phosphate (Dha-P) by an ATP- or phosphoenolpyruvate (PEP)-dependent Dha kinase. Listeria innocua possesses two potential PEP-dependent Dha kinases. One is encoded by 3 of the 11 genes forming the glycerol (gol) operon. This operon also contains golD (lin0362), which codes for a new type of Dha-forming NAD(+)-dependent glycerol dehydrogenase. The subsequent metabolism of Dha requires its phosphorylation via the PEP:sugar phosphotransferase system components enzyme I, HPr, and EIIA(Dha)-2 (Lin0369). P∼EIIA(Dha)-2 transfers its phosphoryl group to DhaL-2, which phosphorylates Dha bound to DhaK-2. The resulting Dha-P is probably metabolized mainly via the pentose phosphate pathway, because two genes of the gol operon encode proteins resembling transketolases and transaldolases. In addition, purified Lin0363 and Lin0364 exhibit ribose-5-P isomerase (RipB) and triosephosphate isomerase activities, respectively. The latter enzyme converts part of the Dha-P into glyceraldehyde-3-P, which, together with Dha-P, is metabolized via gluconeogenesis to form fructose-6-P. Together with another glyceraldehyde-3-P molecule, the transketolase transforms fructose-6-P into intermediates of the pentose phosphate pathway. The gol operon is preceded by golR, transcribed in the opposite orientation and encoding a DeoR-type repressor. Its inactivation causes the constitutive but glucose-repressible expression of the entire gol operon, including the last gene, encoding a pediocin immunity-like (PedB-like) protein. Its elevated level of synthesis in the golR mutant causes slightly increased immunity against pediocin PA-1 compared to the wild-type strain or a pedB-like deletion mutant.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Gene Expression Regulation, Bacterial
  • Listeria / enzymology*
  • Listeria / genetics
  • Listeria / metabolism*
  • Operon
  • Pentose Phosphate Pathway*
  • Phosphoenolpyruvate / metabolism*
  • Phosphotransferases (Alcohol Group Acceptor) / genetics
  • Phosphotransferases (Alcohol Group Acceptor) / metabolism*
  • Sugar Alcohol Dehydrogenases / genetics
  • Sugar Alcohol Dehydrogenases / metabolism*

Substances

  • Phosphoenolpyruvate
  • Sugar Alcohol Dehydrogenases
  • glycerol dehydrogenase
  • Phosphotransferases (Alcohol Group Acceptor)
  • glycerone kinase