title: Involvement of DNA-dependent RNA polymerase in a recA-independent pathway of genetic recombination in Escheria coli.
abstract: Recombinant DNA molecule of phage lambda formed in Escherichia coli in the presence of chloramphenicol and/or rifampin can be assayed by their biological activity. recA- cells were found to be capable of forming recombinant lambda phage DNA in the presence of chloramphenicol. The relatively high recA-independent recombination observed in this system contrasts with the relatively low recA-independent recombination when recombinant phage particles rather than recombinant DNA are titrated. Formation of the recombinant DNA was suppressed by the the addition of rifampin. The introduction of the rif-r mutation into host bacteria made their recombination activity rifampin-resistant. These results show that DNA-dependent RNA polymerase (EC 2.7.7.6) is involved in this recA-independent pathway of recombination, which is named the "Rpo pathway." This is distinct from Red, Int, RecBC, RecE, or Der pathways of recombination. Crossover was much more frequent in the N-PL-cI and cI-PR-O regions than in the A-D and O-S regions. The crossover seems to occur in the regions that are transcribed actively. Some local change of DNA structure caused by transcription might be required for the Rpo pathway of recombination.
mesh_terms: D003090:Coliphages / Q000378:metabolism; D004274:DNA, Recombinant / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism*; D005814:Genes, Viral; D005838:Genotype; D012329:RNA, Bacterial / Q000096:biosynthesis; D011995:Recombination, Genetic / Q000187:drug effects; D012293:Rifampin / Q000494:pharmacology; D013045:Species Specificity; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D004274:DNA, Recombinant; D004279:DNA, Viral; D012329:RNA, Bacterial; D012321:DNA-Directed RNA Polymerases; D012293:Rifampin