Copper sensitivity of cueO mutants of Escherichia coli K-12 and the biochemical suppression of this phenotype

Biochem Biophys Res Commun. 2005 Mar 25;328(4):1205-10. doi: 10.1016/j.bbrc.2005.01.084.


The cueO gene of Escherichia coli encodes a multi-copper oxidase, which contributes to copper tolerance in this bacterium. It was observed that a cueO mutant was highly sensitive to killing by copper ions when cells were grown on defined minimal media. Copper sensitivity was correlated with accumulation of copper in the mutant strain. Growth of the cueO mutant in the presence of copper could be restored by addition of divalent zinc and manganese ions or ferrous iron but not by other first row transition metal ions or magnesium ions. Copper toxicity towards a cueO mutant could also be suppressed by addition of the superoxide quencher 1,2-dihydroxybenzene-3,5-disulfonic acid (tiron), suggesting that a primary cause of copper toxicity is the copper-catalyzed production of superoxide anions in the cytoplasm.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival / drug effects
  • Copper / pharmacokinetics*
  • Copper / pharmacology*
  • Dose-Response Relationship, Drug
  • Drug Resistance, Microbial / physiology
  • Escherichia coli K12 / cytology
  • Escherichia coli K12 / drug effects*
  • Escherichia coli K12 / genetics
  • Escherichia coli K12 / metabolism*
  • Escherichia coli Proteins
  • Metals
  • Mutation
  • Oxidoreductases / genetics
  • Oxidoreductases / metabolism*
  • Phenotype
  • Sensitivity and Specificity
  • Species Specificity
  • Transition Elements / pharmacology*


  • Escherichia coli Proteins
  • Metals
  • Transition Elements
  • Copper
  • Oxidoreductases
  • cueO protein, E coli