Bacillus subtilis CPx-type ATPases: characterization of Cd, Zn, Co and Cu efflux systems

Biometals. 2003 Dec;16(4):497-505. doi: 10.1023/a:1023425321617.

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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / genetics
  • Adenosine Triphosphatases / metabolism*
  • Bacillus subtilis / enzymology*
  • Bacillus subtilis / genetics
  • Bacillus subtilis / metabolism
  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Base Sequence
  • Cadmium / metabolism*
  • Cation Transport Proteins / genetics
  • Cation Transport Proteins / metabolism
  • Cobalt / metabolism*
  • Copper / metabolism*
  • Gene Expression Regulation, Bacterial
  • Genes, Bacterial / genetics
  • Ion Transport
  • Macromolecular Substances
  • Models, Biological
  • Molecular Sequence Data
  • Peptide Library
  • Protein Structure, Tertiary
  • Zinc / metabolism*

Substances

  • Bacterial Proteins
  • Cation Transport Proteins
  • Macromolecular Substances
  • Peptide Library
  • Cadmium
  • Cobalt
  • Copper
  • Adenosine Triphosphatases
  • cadmium translocating ATPase
  • Zinc