The product of the ybdE gene of the Escherichia coli chromosome is involved in detoxification of silver ions

Microbiology (Reading). 2001 Apr;147(Pt 4):965-972. doi: 10.1099/00221287-147-4-965.


Transcription of the ybcZ--ylcA ylcBCD--ybdE region of the Escherichia coli K38 chromosome was analysed by Northern RNA--DNA hybridization, RT-PCR and primer extension. Transcription of a dicistronic ybcZ--ylcA mRNA and a tetracistronic ylcBCD--ybdE mRNA was induced by silver and was initiated from the sigma-70 promoters ylcAp and ylcBp. Expression of beta-galactosidase activity from a Phi(ylcBp--lacZ) operon fusion was also induced by Ag(+) and Cu(2+), but not by Zn(2+). In-frame deletion of ybdE from the chromosome yielded a silver-sensitive E. coli mutant strain which did not differ in its copper resistance from its wild-type strain. On the other hand, deletion of the copA gene for the copper-exporting P-type ATPase CopA resulted in copper sensitivity, but not in silver sensitivity. A Delta ybdE Delta copA double mutant strain behaved towards copper as the Delta copA strain and towards silver as the Delta ybdE strain. Thus, in E. coli, the YlcBCD--YbdE system may be involved in silver- but not in copper resistance, and CopA may be involved in copper- but not in silver resistance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism
  • Blotting, Northern
  • Chromosomes, Bacterial
  • Copper / metabolism
  • Copper / toxicity
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Genes, Bacterial*
  • Genes, Reporter
  • Lac Operon
  • Operon
  • Promoter Regions, Genetic
  • RNA, Bacterial / analysis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Deletion
  • Silver / metabolism*
  • Silver / toxicity


  • Bacterial Proteins
  • CopA protein, Bacteria
  • RNA, Bacterial
  • Silver
  • Copper