title: The antirepressor needed for induction of linear plasmid-prophage N15 belongs to the SOS regulon.
abstract: The physiological conditions and molecular interactions that control phage production have been studied in only a few families of temperate phages. We investigated the mechanisms that regulate activation of lytic development in lysogens of coliphage N15, a prophage that is not integrated into the host chromosome but exists as a linear plasmid with covalently closed ends. We identified the N15 antirepressor gene, antC, and showed that its product binds to and acts against the main phage repressor, CB. LexA binds to and represses the promoter of antC. Mitomycin C-stimulated N15 induction required RecA-dependent autocleavage of LexA and expression of AntC protein. Thus, a cellular repressor whose activity is regulated by DNA damage controls N15 prophage induction.
authors.affiliation: Centre Bioengineering, Russian Academy of Sciences, Prosp. 60-let Oktiabria, Bldg.7-1, Moscow 117312, Russia.
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Mardanov
authors.forename: Nikolai V
authors.initials: NV
authors.lastname: Ravin
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000378:metabolism; D003090:Coliphages / Q000254:growth & development*; D004279:DNA, Viral / Q000378:metabolism; D016685:Mitomycin / Q000494:pharmacology; D008969:Molecular Sequence Data; D010957:Plasmids; D011401:Promoter Regions, Genetic; D039002:Prophages / Q000254:growth & development*; D011485:Protein Binding; D011938:Rec A Recombinases / Q000502:physiology; D012097:Repressor Proteins / Q000037:antagonists & inhibitors; D012697:Serine Endopeptidases / Q000378:metabolism; D014764:Viral Proteins / Q000037:antagonists & inhibitors / Q000096:biosynthesis* / Q000235:genetics*; D014775:Virus Activation / Q000502:physiology*; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D004279:DNA, Viral; D016685:Mitomycin; D011938:Rec A Recombinases; D012097:Repressor Proteins; D012697:Serine Endopeptidases; D014764:Viral Proteins; D000099160:LexA Repressor Protein; C099483:CB protein, N15 bacteriophage