Characterization of copper-inducible promoters regulated by CpxA/CpxR in Escherichia coli.
The copper stimulon in Escherichia coli consists of four regulons, the CueR-, CusS/CusR-, CpxA/CpxR-, and YedV/YedW regulons. E. coli mutants defective in cpxRA showed higher sensitivity to copper than the wild type. A total of 15 promoters were found to be induced in E. coli culture upon exposure to copper in a CpxA/CpxR-dependent manner. After gel-shift and DNase I foot-printing analyses, a conserved tandem repeat of pentanucleotide sequence, GTAAA(N)(4-8)GTAAA, with a conserved A of 4-bp upstream of each pentamer, was identified to be the CpxR-binding site. The difference in the orientation and location of the CpxR box is discussed with respect to the regulation mechanism among CpxR-regulon genes.
Yamamoto
Kaneyoshi
K
Department of Advanced Bioscience, Kinki University, Nakamachi, Nara 631-8505, Japan. kyamam@nara.kindai.ac.jp
Ishihama
Akira
A
D001483:Base Sequence; D003300:Copper / Q000494:pharmacology*; D018983:DNA Footprinting; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009154:Mutation; D011401:Promoter Regions, Genetic; D018085:Regulon
D029968:Escherichia coli Proteins; D003300:Copper