[Identification of the plasmid R1drd-19 region complementing the mutant phenotype recB- in Escherichia coli K12 strain]

Mol Gen Mikrobiol Virusol. 1985 Nov;(11):16-20.
[Article in Russian]


Plasmid R1-19 and its copy number mutants markedly increase the recombinational efficiency of a recB- strain of E. coli K12 and its resistance to the lethal action of UV and mitomycin C. These effects are associated with the appearance of a new ATP-dependent exonuclease activity in recB- cells known to be deficient in the ATP-dependent exonuclease V. Using hybrid plasmids carrying different EcoRI fragments of R1-19 (in the pSF124 vector), the gene(s) responsible for effect of R1-19 in recB-cells were localized in the EcoRI-C fragment (8.5 MD) belonging to the RTF portion of R1-19. Expression of the gene(s) in hybrid plasmids depends on the orientation of EcoRI-C fragment in the vector. The copy number of the EcoRI-C fragment was not strictly correlated with the degree of expression of the effects in the recB- mutant.

MeSH terms

  • DNA Restriction Enzymes
  • Escherichia coli / genetics*
  • Genes, Bacterial*
  • Genetic Complementation Test
  • Mutation*
  • Phenotype
  • Plasmids*


  • DNA Restriction Enzymes