title: Phleomycin-stimulated degradation of deoxyribonucleic acid in Escherichia coli.
abstract: Phleomycin stimulates the degradation of DNA by energy-dependent endonuclease and exonuclease reactions in Escherichia coli rec(+) cells and in recB(-) and recC(-) cells that lack an adenosine triphosphate-dependent nuclease functioning in the repair of ultraviolet (UV) lesions. Exonuclease activity is blocked in T4 phage-infected cells. The endonuclease reaction produces 10(7)-dalton segments resembling those produced in colicin E2-treated cells. These differ from the random-sized segments produced in UV-irradiated cells, or the 10(6)-dalton segments made in T4 phage-infected cells. A mutant selected for phleomycin tolerance is cross-tolerant to colicin E2, and some mutants selected for colicin E2 tolerance are cross-tolerant to phleomycin. On the basis of these cross-tolerances and the similarities between the effects of phleomycin and E2-stimulated nucleases, the suggestion is made that both agents may stimulate the same nuclease reactions in E. coli cells.
mesh_terms: D000903:Antibiotics, Antineoplastic / Q000494:pharmacology*; D001673:Biodegradation, Environmental; D003090:Coliphages / Q000378:metabolism; D004260:DNA Repair / Q000187:drug effects; D004269:DNA, Bacterial / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology / Q000378:metabolism* / Q000528:radiation effects; D005092:Exonucleases / Q000378:metabolism; D009154:Mutation; D009691:Nucleic Acid Denaturation; D010455:Peptides / Q000494:pharmacology; D011830:Radiation Effects; D011995:Recombination, Genetic; D012995:Solubility; D013936:Thymidine / Q000378:metabolism; D014316:Tritium; D014466:Ultraviolet Rays
chemical_list: D000903:Antibiotics, Antineoplastic; D004269:DNA, Bacterial; D010455:Peptides; D014316:Tritium; D004720:Endonucleases; D005092:Exonucleases; D013936:Thymidine