Analysis of the promoter activities of the genes encoding three quinoprotein alcohol dehydrogenases in Pseudomonas putida HK5.
The transcriptional regulation of three distinct alcohol oxidation systems, alcohol dehydrogenase (ADH)-I, ADH-IIB and ADH-IIG, in Pseudomonas putida HK5 was investigated under various induction conditions. The promoter activities of the genes involved in alcohol oxidation were determined using a transcriptional lacZ fusion promoter-probe vector. Ethanol was the best inducer for the divergent promoters of qedA and qedC, encoding ADH-I and a cytochrome c, respectively. Primary and secondary C3 and C4 alcohols and butyraldehyde specifically induced the divergent promoters of qbdBA and aldA, encoding ADH-IIB and an NAD-dependent aldehyde dehydrogenase, respectively. The qgdA promoter of ADH-IIG responded well to (S)-(+)-1,2-propanediol induction. In addition, the roles of genes encoding the response regulators exaE and agmR, located downstream of qedA, were inferred from the properties of exaE- or agmR-disrupted mutants and gene complementation tests. The gene products of both exaE and agmR were strictly necessary for qedA transcription. The mutation and complementation studies also suggested a role for AgmR, but not ExaE, in the transcriptional regulation of qbdBA (ADH-IIB) and qgdA (AGH-IIG). A hypothetical scheme describing a regulatory network, which directs expression of the three distinct alcohol oxidation systems in P. putida HK5, was derived.
Promden
Worrawat
W
Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Vangnai
Alisa S
AS
Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
Toyama
Hirohide
H
Department of Bioscience and Biotechnology, Faculty of Agriculture, University of the Ryukyus, Okinawa 903-0213, Japan.
Matsushita
Kazunobu
K
Department of Biological Chemistry, Faculty of Agriculture, Yamaguchi University, Yamaguchi 753-8515, Japan.
Pongsawasdi
Piamsook
P
Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand.
D000429:Alcohol Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D015964:Gene Expression Regulation, Bacterial; D005810:Multigene Family; D011401:Promoter Regions, Genetic; D016958:Pseudomonas putida / Q000201:enzymology* / Q000235:genetics; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D000429:Alcohol Oxidoreductases; C019641:alcohol dehydrogenase (acceptor)