Characterization of Copper-Inducible Promoters Regulated by CpxA/CpxR in Escherichia coli
The copper stimulon in <I>Escherichia coli</I> consists of four regulons, the CueR-, CusS/CusR-, CpxA/CpxR-, and YedV/YedW regulons. <I>E. coli</I> mutants defective in <I>cpxRA</I> showed higher sensitivity to copper than the wild type. A total of 15 promoters were found to be induced in <I>E. coli</I> 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)<SUB>4–8</SUB>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.
- Bioscience, biotechnology, and biochemistry
Bioscience, biotechnology, and biochemistry 70(7), 1688-1695, 2006-07-23
Japan Society for Bioscience, Biotechnology, and Agrochemistry