title: Effects of chloramphenicol and caffeine on postreplication repair in uvr A- umuC- und uvrA- recF- strains of Escherichia coli K-12.
abstract: Postreplication repair and its inhibition by chloramphenicol and caffeine, as seen in alkaline sucrose gradients, were compared between a uv non-mutable strain uvrA- umuC- and normally mutable strains uvrA- recF- and uvrA- umu+rec+ of Escherichia coli K-12. The uvrA- umuC- strain performed postreplication repair as efficiently as the parental strain, while the repair in uvrA- recF- strain was dependent on UV dose. Both chloramphenicol and caffeine inhibited postreplication repair to an equal extent of about 25%, and 10%, respectively, in all three uvrA- strains of umuC36, recF- and umu+rec+. These observations suggest that postreplication repair is largely not responsible for UV mutagenesis.
mesh_terms: D002110:Caffeine / Q000494:pharmacology*; D002701:Chloramphenicol / Q000494:pharmacology*; D004260:DNA Repair / Q000187:drug effects*; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics / Q000528:radiation effects; D009154:Mutation; D010641:Phenotype; D013045:Species Specificity; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D002110:Caffeine; D002701:Chloramphenicol