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 cadClcadA 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.