A bacterial basic region leucine zipper histidine kinase regulating toluene degradation.
The two-component signal transduction pathways in bacteria use a histidine-aspartate phosphorelay circuit to mediate cellular changes in response to environmental stimuli. Here we describe a novel two-component todST system, which activates expression of the toluene degradation (tod) pathway in Pseudomonas putida F1. The todS gene is predicted to encode a sensory hybrid kinase with two unique properties--a basic region leucine zipper dimerization motif at the N terminus and a duplicated histidine kinase motif. Evidence from a synthetic peptide model suggests that TodS binds as a dimer to a pseudopalindromic sequence (5'-TGACTCA), which resembles the recognition sequence of the eukaryotic transcription factors Fos and Jun. These results provide additional evidence that bacteria and eukaryotes share common regulatory motifs. The todT gene product, a response regulator, was overproduced as a fusion protein in Escherichia coli, and the purified protein was found to bind specifically to a 6-bp palindromic DNA structure in the tod control region. The phosphorylated form of TodT appears to be the activator of tod structural genes. This is the first report of a two-component system that regulates aromatic metabolism in bacteria.
Lau
P C
PC
Biotechnology Research Institute, National Research Council of Canada, Montreal, QC. peter.lau@nrc.ca
Wang
Y
Y
Patel
A
A
Labbé
D
D
Bergeron
H
H
Brousseau
R
R
Konishi
Y
Y
Rawlings
M
M
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000145:classification / Q000235:genetics; D001673:Biodegradation, Environmental; D018983:DNA Footprinting; D004252:DNA Mutational Analysis; D019281:Dimerization; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D000071677:Histidine Kinase; D016350:Leucine Zippers / Q000235:genetics*; D008565:Membrane Proteins / Q000235:genetics; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010446:Peptide Fragments; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D016958:Pseudomonas putida / Q000201:enzymology / Q000235:genetics*; D011994:Recombinant Proteins / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014050:Toluene / Q000378:metabolism*; D015534:Trans-Activators / Q000235:genetics*; D018808:Transcription Factor AP-1 / Q000378:metabolism
D001426:Bacterial Proteins; D008565:Membrane Proteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; C104650:TodT protein, Pseudomonas putida; C092771:TodX protein, Pseudomonas putida; D015534:Trans-Activators; D018808:Transcription Factor AP-1; D014050:Toluene; D011494:Protein Kinases; D000071677:Histidine Kinase; C104649:TodS protein, Pseudomonas putida