title: Repair and plasmid R46 mediated mutation requires inducible functions in Proteus mirabilis.
abstract: In Proteus mirabilis nalidixic acid or a predose of UV induce Rec protein formation, a portion of post-UV replication repair and "post-UV replication enhancement." These inducible functions are not significantly affected by the plasmid R46, which renders P. mirabilis efficiently UV-mutable. The R46-mediated UV induction of rif mutations requires additional inducible functions, as existing after nalidixic acid treatment in rec+ strains. After a nalidixic acid pretreatment UV efficient induction of rif mutations occurs without an otherwise obligatory period of post-UV incubation prior to plating on rifampicin agar. THe inducible character of this "qualification" of plasmid R46-mediated UV mutagenesis in P. mirabilis is evident from the inhibitory effects of chloramphenicol and starvation. Constitutive high-level synthesis of Rec protein in cells harboring the recombinant (multi-copy) rec+ plasmid pPM1 reduced plasmid R46-mediated UV mutagenesis, probably by preventing (inducible?) functions required by the plasmid R46 repair-mutator.
mesh_terms: D004260:DNA Repair; D009154:Mutation; D009268:Nalidixic Acid / Q000494:pharmacology; D010641:Phenotype; D010957:Plasmids; D011513:Proteus mirabilis / Q000235:genetics* / Q000528:radiation effects; D014466:Ultraviolet Rays
chemical_list: D009268:Nalidixic Acid