title: Escherichia coli dihydroxyacetone kinase controls gene expression by binding to transcription factor DhaR.
abstract: Dihydroxyacetone (Dha) kinases are a sequence-conserved family of enzymes, which utilize either ATP (in animals, plants, bacteria) or the bacterial phosphoenolpyruvate carbohydrate phosphotransferase system (PTS) as a source of high-energy phosphate. The PTS-dependent kinase of Escherichia coli consists of three subunits: DhaK contains the Dha binding site, DhaL contains ADP as cofactor for the double displacement of phosphate from DhaM to Dha, and DhaM provides a phospho-histidine relay between the PTS and DhaL::ADP. DhaR is a transcription activator belonging to the AAA+ family of enhancer binding proteins. It stimulates transcription of the dhaKLM operon from a sigma70 promoter and autorepresses dhaR transcription. Genetic and biochemical studies indicate that the enzyme subunits DhaL and DhaK act antagonistically as coactivator and corepressor of the transcription activator by mutually exclusive binding to the sensing domain of DhaR. In the presence of Dha, DhaL is dephosphorylated and DhaL::ADP displaces DhaK and stimulates DhaR activity. In the absence of Dha, DhaL::ADP is converted by the PTS to DhaL::ATP, which does not bind to DhaR.
authors.affiliation: Departement für Chemie und Biochemie, Universität Bern, Bern, Switzerland.
authors.forename: Christoph
authors.initials: C
authors.lastname: Bächler
authors.forename: Philipp
authors.initials: P
authors.lastname: Schneider
authors.forename: Priska
authors.initials: P
authors.lastname: Bähler
authors.forename: Ariel
authors.initials: A
authors.lastname: Lustig
authors.forename: Bernhard
authors.initials: B
authors.lastname: Erni
mesh_terms: D000595:Amino Acid Sequence; D015153:Blotting, Western; D020134:Catalytic Domain; D002850:Chromatography, Gel; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D008969:Molecular Sequence Data; D009876:Operon; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000378:metabolism*; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; C095090:DhaR protein, E coli; D029968:Escherichia coli Proteins; D015534:Trans-Activators; D017853:Phosphotransferases (Alcohol Group Acceptor); C023132:glycerone kinase