Metalloregulation in Bacillus subtilis: the copZ chromosomal gene is involved in cadmium resistance.
The copZ gene of Bacillus subtilis encodes a copper chaperon CopZ that donates copper to the copper transporter CopA. Both genes copZ and copA are clustered to an operon and its promoter is regulated by Cu ions and CueR, a Mer-like transcriptional activator. Here we show that cadmium ions activate copZA expression as strong as copper ions. Northern hybridization analysis showed that copper and cadmium both induce the synthesis of a 2.7 kb copZA transcript and a 250 bp copZ transcript. A copA deletion mutant was sensitive to copper, whereas a copZ deletion resulted in an increased sensitivity to cadmium and copper. Transcription of the cadmium resistance gene cadA, which is adjacent to the copZA cluster, is extremely reduced in a copZ deletion strain. Transformation of copZ in trans restores wild type resistance to cadmium and copper in a copZ deletion strain. This excludes any polar effect and proves that the copZ encoded protein is important for copper and cadmium resistance.
Solovieva
Irina M
IM
Molecular and Radiation Biophysics Division, St. Petersburg Nuclear Physics Institute of the Russian Academy of Sciences. solovieva@em.uni-frankfurt.de
Entian
Karl-Dieter
KD
D001412:Bacillus subtilis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D002104:Cadmium / Q000378:metabolism*; D002876:Chromosomes, Bacterial; D003300:Copper / Q000378:metabolism*; D017353:Gene Deletion; D007763:Lac Operon; D018832:Molecular Chaperones / Q000235:genetics* / Q000378:metabolism; D010641:Phenotype; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014158:Transcription, Genetic
D001426:Bacterial Proteins; C071263:CopA protein, Bacteria; C092379:CopZ protein, Enterococcus hirae; D018832:Molecular Chaperones; D015534:Trans-Activators; D002104:Cadmium; D003300:Copper