title: Properties of the nonlethal recombinational repair x and y mutants of bacteriophage T4. II. DNA synthesis.
abstract: The bacteriophage T4 recombination-deficient mutants x and y exhibited decreased rates of DNA synthesis as compared to wild-type T4. Mutant-induced DNA synthesis was more sensitive to mitomycin C than was wild-type synthesis. However, DNA synthesis in mutant- and wild-type-infected cells exhibited the same sensitivity to UV light and X-irradiation. When high-specific-activity label was administered at various times postinfection, mutant DNA synthesis resembled that of wild type for 12 min. after which time mutant-induced incorporation was greatly decreased and sensitive to mitomycin C as compared to that of the wild type. Rifampin and chloramphenicol studies indicated that the gene products necessary for synthesis measured at 15 min postinfection, including those of x+ and y+ were transcribed within 2 min and translated within 8 min postinfection. Administration of chloramphenicol to mutant x- or mutant y-infected cells exactly 8 min postinfection, however, allowed for increased synthesis at 15 min that was sensitive to mitomycin C. Cells coinfected with T4+ and T4x or T4x and T4y retained a reduced mutant-type synthesis, whereas cells coinfected with T4+ and T4y exhibited a synthesis more closely resembling that of wild type.
mesh_terms: D002701:Chloramphenicol / Q000494:pharmacology; D003090:Coliphages / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D004260:DNA Repair; D004279:DNA, Viral / Q000096:biosynthesis*; D008937:Mitomycins / Q000494:pharmacology; D009154:Mutation; D011995:Recombination, Genetic; D012293:Rifampin / Q000494:pharmacology; D014466:Ultraviolet Rays; D014965:X-Rays
chemical_list: D004279:DNA, Viral; D008937:Mitomycins; D002701:Chloramphenicol; D012293:Rifampin