Isolation of gene fusions (soi::lacZ) inducible by oxidative stress in Escherichia coli

Proc Natl Acad Sci U S A. 1988 Jul;85(13):4799-803. doi: 10.1073/pnas.85.13.4799.


Mu dX phage was used to isolate three gene fusions to the lacZ gene (soi::lacZ; soi for superoxide radical inducible) that were induced by treatment with superoxide radical anion generators such as paraquat and plumbagin. The induction of beta-galactosidase in these fusion strains with the superoxide radical generating agents required aerobic metabolism. Hyperoxygenation (i.e., bubbling of cultures with oxygen gas) also induced the fusions. On the other hand, hydrogen peroxide did not induce the fusions at concentrations that are known to invoke an adaptive response. Introduction of oxyR, htpR, or recA mutations did not affect the induction. Two of the fusion strains exhibited increased sensitivity to paraquat but not to hydrogen peroxide. The third fusion strain showed no increased sensitivity to either agent. All three fusions were located in the 45- to 61-min region of the Escherichia coli chromosome.

Publication types

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

MeSH terms

  • Aerobiosis
  • Bacteriophage mu / physiology
  • DNA Repair
  • DNA Transposable Elements / drug effects
  • Escherichia coli / drug effects
  • Escherichia coli / genetics*
  • Escherichia coli / metabolism
  • Free Radicals
  • Genes / drug effects*
  • Genes, Bacterial
  • Hydrogen Peroxide / pharmacology
  • Naphthoquinones / pharmacology
  • Oxidation-Reduction
  • Oxygen / pharmacology
  • Paraquat / pharmacology
  • Recombinant Fusion Proteins / biosynthesis
  • Recombinant Fusion Proteins / genetics*
  • Recombinant Proteins / genetics*
  • Recombination, Genetic / drug effects*
  • Superoxides / pharmacology
  • beta-Galactosidase / biosynthesis
  • beta-Galactosidase / genetics


  • DNA Transposable Elements
  • Free Radicals
  • Naphthoquinones
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • Superoxides
  • Hydrogen Peroxide
  • beta-Galactosidase
  • Paraquat
  • Oxygen
  • plumbagin