A soluble two-component regulatory system controls expression of quinoprotein ethanol dehydrogenase (QEDH) but not expression of cytochrome c(550) of the ethanol-oxidation system in Pseudomonas aeruginosa.
The regulation of the divergent promoters of the exaAB genes in Pseudomonas aeruginosa ATCC 17933, in which exaA encodes a quinoprotein ethanol dehydrogenase and exaB codes for a cytochrome c(550), was studied. Using transcriptional lacZ fusions, promoter activity during growth on several substrates was measured. These promoter-probe vectors were also used to identify regulatory mutants defective in exaAB induction. Transcription from both exaA and exaB was reduced significantly in four mutants. Two other mutants showed transcription from exaA that was reduced, but higher than wild-type transcription from exaB. The genes that are needed for exaA promoter induction were sequenced and found to encode a two-component regulatory system: a histidine sensor kinase, which lacks a transmembrane helical N-terminus and is presumably located in the cytoplasm, and a response regulator. The phenotypic characterization and restoration of the wild-type behaviour of the different regulatory mutants produced by different cosmids and subclones indicate that six different genes may be involved in regulating ethanol oxidation in P. aeruginosa.
Schobert
Max
M
Fachgebiet Technische Biochemie, Institut für Biotechnologie der Technischen Universität Berlin, Seestraße 13, D-13353 Berlin, Germany1.
Görisch
Helmut
H
Fachgebiet Technische Biochemie, Institut für Biotechnologie der Technischen Universität Berlin, Seestraße 13, D-13353 Berlin, Germany1.
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003574:Cytochrome c Group / Q000235:genetics / Q000378:metabolism; D000431:Ethanol / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D005809:Genes, Regulator / Q000235:genetics; D000071677:Histidine Kinase; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D011401:Promoter Regions, Genetic / Q000235:genetics; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D012995:Solubility; D014157:Transcription Factors; D014158:Transcription, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D003574:Cytochrome c Group; C433522:ExaE protein, Pseudomonas aeruginosa; D014157:Transcription Factors; D000431:Ethanol; C031732:cytochrome C-550; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor); D011494:Protein Kinases; C433521:ExaD protein, Pseudomonas aeruginosa; D000071677:Histidine Kinase; D001616:beta-Galactosidase