Expression of Bacillus stearothermophilus LV cadmium resistance genes in Escherichia coli causes hypersensitivity to cadmium chloride

Abstract

Determination of the nucleotide sequence of a 4.5-kb chromosomal DNA fragment of Bacillus stearothermophilus LV revealed two open reading frames (ORFs) of 121 and 727 amino acids (aa) that exhibit a high degree of similarity with the cadC and cadA cadmium resistance genes of a number of microorganisms. Transfer and expression of the B. stearothermophilus LV cadA or cadC/ cadA genes in E. coli caused increased cadmium chloride susceptibility in the bacterial host. Transfer of cadC alone did not result in any detectable phenotypic change in E. coli.