The creation of a camptothecin-sensitive Escherichia coli based on the expression of the human topoisomerase I

Gene. 1995 Dec 29;167(1-2):69-74. doi: 10.1016/0378-1119(95)00608-7.


The synthesis of the human topoisomerase I (Topo I) in Escherichia coli (Ec) results in phenotypes consistent with the appearance of a DNA-relaxing activity. High-level expression was problematic and recloning the gene in a reduced-copy-number plasmid under more stringently regulated control produced a stable plasmid. An Ec strain with an inducible sensitivity to the eukaryotic Topo I poison, camptothecin (CPT), was constructed by introducing a mutation (imp4312) known to enhance the permeability of Ec to a wide variety of compounds. We are able to infer that CPT sensitivity in Ec involves DNA damage by noting elevated sensitivity in a repair-deficient recA strain and by observing the induction of a sulA::lac fusion following exposure to the drug.

MeSH terms

  • Camptothecin / pharmacology*
  • Cloning, Molecular
  • DNA Topoisomerases, Type I / genetics*
  • Enzyme Inhibitors / pharmacology
  • Escherichia coli / genetics
  • Genetic Complementation Test
  • Humans
  • Recombinant Proteins
  • Topoisomerase I Inhibitors


  • Enzyme Inhibitors
  • Recombinant Proteins
  • Topoisomerase I Inhibitors
  • DNA Topoisomerases, Type I
  • Camptothecin