A second gene in the Staphylococcus aureus cadA cadmium resistance determinant of plasmid pI258.
Two open reading frames on a 3.7-kb BglII-XbaI fragment which encodes the Staphylococcus aureus cadA cadmium (and zinc) resistance determinant of plasmid pI258 were identified (G. Nucifora, L. Chu, T. K. Misra, and S. Silver, Proc. Natl. Acad. Sci. USA 86:3544-3548, 1989). The [35S]methionine-labelled protein products of the 727-amino-acid CadA ATPase and of the 122-amino-acid CadC polypeptide in Escherichia coli were identified by using the T7 RNA polymerase-promoter expression system. A truncated CadA polypeptide (402 amino acids) did not confer resistance in S. aureus but was expressed in E. coli under control of the T7 RNA polymerase-promoter. Removal of 678 nucleotides from the 5' end of the published sequence (which includes the cadA promoter) abolished resistance to cadmium, whereas a 146-nucleotide-shorter deletion was without effect. The cadC gene is needed in addition to cadA for full resistance to cadmium in S. aureus and Bacillus subtilis. cadC functions both in cis and in trans.
Department of Microbiology and Immunology, University of Illinois, College of Medicine, Chicago 60680.
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D001412:Bacillus subtilis / Q000187:drug effects / Q000235:genetics / Q000254:growth & development; D002104:Cadmium / Q000494:pharmacology*; D002872:Chromosome Deletion; D003001:Cloning, Molecular; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D007700:Kinetics; D016366:Open Reading Frames; D009876:Operon; D011401:Promoter Regions, Genetic; D011815:R Factors; D015183:Restriction Mapping; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development; D015032:Zinc / Q000494:pharmacology
D002104:Cadmium; D015032:Zinc