title: [Identification of the plasmid R1drd-19 region complementing the mutant phenotype recB- in Escherichia coli K12 strain].
abstract: 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: D004262:DNA Restriction Enzymes; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005816:Genetic Complementation Test; D009154:Mutation; D010641:Phenotype; D010957:Plasmids
chemical_list: D004262:DNA Restriction Enzymes
vernacular_title: Identifikatsiia raĭona plazmidy R1drd-19, komplementiruiushchego mutantnyĭ fenotip recB- shtamma Escherichia coli K12.