title: Bacillus subtilis CPx-type ATPases: characterization of Cd, Zn, Co and Cu efflux systems.
abstract: Metal ion homeostasis requires the balanced expression of metal ion uptake systems, when metals are limiting, and corresponding efflux or storage systems, when metals are in excess. CPx-type ATPases are a family of membrane-bound transporters that often function to export toxic metals from cells. The Bacillus subtilis genome encodes three CPx-type ATPases: zosA, yvgW and yvgX. We demonstrate that yvgW and yvgX encode CadA and CopA, respectively, and that these genes function in metal ion resistance. A cadA mutant was sensitive to Cd(II), Zn(II) and Co(II), but not copper. Transcription of cadA initiates from a single, sigmaA-type promoter and was induced by Cd(II), Zn(II), and Co(II). The adjacent copZA operon is expressed as a bicistronic transcript from a sigmaA-type promoter and is selectively induced by copper. Mutation of either copZ, encoding a metallochaperone, or copA sensitizes the cells to copper but not to other metal ions.
authors.affiliation: Department of Microbiology, Cornell University, Ithaca, NY 14853-8101, USA.
authors.forename: Ahmed
authors.initials: A
authors.lastname: Gaballa
authors.forename: John D
authors.initials: JD
authors.lastname: Helmann
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002104:Cadmium / Q000378:metabolism*; D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D003035:Cobalt / Q000378:metabolism*; D003300:Copper / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial / Q000235:genetics; D017136:Ion Transport; D046911:Macromolecular Substances; D008954:Models, Biological; D008969:Molecular Sequence Data; D019151:Peptide Library; D017434:Protein Structure, Tertiary; D015032:Zinc / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D027682:Cation Transport Proteins; D046911:Macromolecular Substances; D019151:Peptide Library; D002104:Cadmium; D003035:Cobalt; D003300:Copper; D000251:Adenosine Triphosphatases; C059771:cadmium translocating ATPase; D015032:Zinc