Molecular cloning and sequence analysis of the lysR gene from the extremely thermophilic eubacterium, Thermus thermophilus HB27.
We have isolated a lysine-auxotrophic and kanamycin-resistant mutant from an extreme thermophile, Thermus thermophilus HB27. This mutant showed the lysA- or lysR- genotype since it could not grow on the minimal plate which contained diaminopimelic acid. Sequence analysis of the clones which could rescue the Lys- mutant indicated the lysR gene. The lysR gene overlapped with the rimK gene for the modification enzyme of ribosomal protein S6. In the Lys- mutant, the lysR gene was disrupted and the C-terminus region of the RimK protein was different from that of the wild-type, which contributed to the Lys- and kanamycin-resistant phenotype. The deduced amino acid sequence of the lysR gene showed 20.9% identity with the LysR protein of Escherichia coli. The percentage of use of cytosine or guanine in the third letter of the codons in the lysR gene was only 67.4%. We also determined that the argC gene encoding N-acetyl-gamma-glutamyl phosphate reductase and the argB gene encoding acetylglutamate kinase were located immediately upstream of the lysR gene.
Kosuge
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Institute of Applied Biochemistry, University of Tsukuba, Ibaraki, Japan.
Hoshino
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D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics*; D001483:Base Sequence; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000032:analysis; D015964:Gene Expression Regulation, Bacterial; D007612:Kanamycin / Q000494:pharmacology; D007613:Kanamycin Resistance; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009876:Operon; D017422:Sequence Analysis, DNA; D016963:Thermus thermophilus / Q000187:drug effects / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D004269:DNA, Bacterial; D014157:Transcription Factors; D007612:Kanamycin; C073470:LysR protein, Bacteria