Identification of a membrane protein and a truncated LysR-type regulator associated with the toluene degradation pathway in Pseudomonas putida F1.
A 3 kb DNA region upstream of the toluene degradation (tod) genes, todFC1C2BADEGIH, in Pseudomonas putida F1 (PpF1) was sequenced. Two divergently arranged open reading frames, todR and todX, were identified. A toluene-inducible promoter was localized in front of todX, and the transcription start point was mapped. This promoter is probably responsible for the expression of all tod structural genes. TodX was found to be a membrane protein. Its predicted amino acid sequence (453 residues; M(r) 48,265) exhibits considerable similarity with the FadL protein of Escherichia coli, an outer membrane protein required for binding and transport of long-chain fatty acids. An apparent function of TodX is likely to be involved in facilitating the delivery of exogenous toluene inside the PpF1 cells. The sequence of TodR (100 residues) exhibits extensive homology with the DNA-binding domain of transcriptional activators of the LysR family, but todR was found to have a negligible role in tod gene regulation.
Wang
Y
Y
Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec.
Rawlings
M
M
Gibson
D T
DT
Labbé
D
D
Bergeron
H
H
Brousseau
R
R
Lau
P C
PC
D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D001673:Biodegradation, Environmental; D015964:Gene Expression Regulation, Bacterial; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics; D009876:Operon / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D016958:Pseudomonas putida / Q000235:genetics* / Q000378:metabolism; D012329:RNA, Bacterial / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017384:Sequence Deletion / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D014050:Toluene / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic / Q000235:genetics
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D008565:Membrane Proteins; D012329:RNA, Bacterial; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C092770:TodR protein, Pseudomonas putida; C092771:TodX protein, Pseudomonas putida; D014157:Transcription Factors; D014050:Toluene; C073470:LysR protein, Bacteria