title: Killing of Escherichia coli cells modulated by components of the stability system ParD of plasmid R1.
abstract: The proteins P10 and P12 have been shown to be gene products of a new stability system, ParD, of plasmid R1. It is now shown that an R1 miniplasmid, pAB112, carrying a trans-complementable amber mutation in the gene of the P10 protein, is lethal for the host in the absence of suppression. This lethal effect is suppressed in a supF background and also by deletions in pAB112 that affect the gene of the P12 protein. These data indicate that the P12 protein has a lethal effect on the host and that this effect is neutralized by the P10 protein. The possibility that the stabilization conferred by the ParD system could be due to a counterselection, mediated by P12, of cells that lose the plasmid at cell division, is discussed.
authors.affiliation: Centro de Investigaciones Biológicas, (C.S.I.C.), Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Bravo
authors.forename: S
authors.initials: S
authors.lastname: Ortega
authors.forename: G
authors.initials: G
authors.lastname: de Torrontegui
authors.forename: R
authors.initials: R
authors.lastname: Díaz
mesh_terms: D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005804:Genes, Lethal; D009154:Mutation; D010641:Phenotype; D011815:R Factors; D013489:Suppression, Genetic