title: Novel listerial glycerol dehydrogenase- and phosphoenolpyruvate-dependent dihydroxyacetone kinase system connected to the pentose phosphate pathway.
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.
authors: INRA, UMR1319 Microbiologie de l'Alimentation au Service de la Santé Humaine, Jouy en Josas, France.
authors: Céline
authors: C
authors: Monniot
authors: Arthur Constant
authors: AC
authors: Zébré
authors: Francine Moussan Désirée
authors: FM
authors: Aké
authors: Josef
authors: J
authors: Deutscher
authors: Eliane
authors: E
authors: Milohanic
mesh_terms: D015964:Gene Expression Regulation, Bacterial; D008087:Listeria / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D009876:Operon; D010427:Pentose Phosphate Pathway; D010728:Phosphoenolpyruvate / Q000378:metabolism*; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000235:genetics / Q000378:metabolism*; D013401:Sugar Alcohol Dehydrogenases / Q000235:genetics / Q000378:metabolism*
chemical_list: D010728:Phosphoenolpyruvate; D013401:Sugar Alcohol Dehydrogenases; C020672:glycerol dehydrogenase; D017853:Phosphotransferases (Alcohol Group Acceptor); C023132:glycerone kinase