title: Translational control and differential RNA decay are key elements regulating postsegregational expression of the killer protein encoded by the parB locus of plasmid R1.
abstract: The parB locus of plasmid R1, which mediates plasmid stability via postsegregational killing of plasmid-free cells, encodes two genes, hok and sok. The hok gene product is a potent cell-killing protein. The hok gene is regulated at the translational level by the sok gene-encoded repressor, a small anti-sense RNA complementary to the hok mRNA. The hok mRNA is extraordinarily stable, while the sok RNA decays rapidly. The mechanism of postsegregational killing is explained by the following model; the sok RNA molecule rapidly disappears in cells that have lost a parB-carrying plasmid, leading to translation of the stable hok mRNA. Consequently, the Hok protein is synthesized and killing of the plasmid-free cell follows.
authors: Department of Microbiology, Technical University of Denmark, Lyngby-Copenhagen.
authors: K
authors: K
authors: Gerdes
authors: K
authors: K
authors: Helin
authors: O W
authors: OW
authors: Christensen
authors: A
authors: A
authors: Løbner-Olesen
mesh_terms: D001483:Base Sequence; D002874:Chromosome Mapping; D004926:Escherichia coli; D005786:Gene Expression Regulation; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014176:Protein Biosynthesis; D011815:R Factors / Q000235:genetics*; D012329:RNA, Bacterial / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012293:Rifampin / Q000494:pharmacology; D013489:Suppression, Genetic
chemical_list: D012329:RNA, Bacterial; D012333:RNA, Messenger; D012293:Rifampin