n-Hexane sensitivity of Escherichia coli due to low expression of imp/ostA encoding an 87 kDa minor protein associated with the outer membrane.
Most Escherichia coli strains are resistant to n-hexane. E. coli OST4251 is a n-hexane-sensitive strain that was constructed by transferring the n-hexane-sensitive phenotype from a n-hexane-sensitive strain by P1 transduction. OST4251 is resistant to diphenyl ether, which is less harmful than n-hexane to micro-organisms. The genetic determinant responsible for this subtle difference in the solvent resistance is mapped at 1.2 min on the E. coli chromosome. Nucleotide sequence analysis showed that IS2 and IS5 had integrated upstream of the imp/ostA structural gene in OST4251. The integration of IS2 decreased the activity of the imp/ostA promoter. A product of the gene was identified immunologically as an 87 kDa minor protein associated with the outer membrane. Upon transformation with plasmids containing the imp/ostA gene, OST4251 produced a high level of the gene product in the membrane and acquired n-hexane resistance. Thus, the low level of promoter activity resulted in low Imp production and the n-hexane-sensitivity phenotype. It is likely that the gene product contributes to n-hexane resistance by reducing the influx of n-hexane.
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Shigeo
S
Abe
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Tomohisa
T
Okutsu
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Harushi
H
Nakajima
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Nobuto
N
Kakuda
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Iwao
I
Ohtsu
Department of Biological Information, Graduate School of Bioscience and Biotechnology, Tokyo Institute of Technology, Nagatsuta 4259, Midori-ku, Yokohama 226-8501, Japan.
Rikizo
R
Aono
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism*; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D024881:Drug Resistance, Bacterial / Q000235:genetics; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism*; D006586:Hexanes / Q000494:pharmacology*; D008969:Molecular Sequence Data; D009154:Mutation; D010647:Phenyl Ethers / Q000494:pharmacology; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D012997:Solvents / Q000494:pharmacology; D014161:Transduction, Genetic
D001425:Bacterial Outer Membrane Proteins; D004251:DNA Transposable Elements; D029968:Escherichia coli Proteins; D006586:Hexanes; C475958:LptD protein, E coli; D010647:Phenyl Ethers; D012997:Solvents; C026385:n-hexane; C031538:phenyl ether