title: Genetic basis of the MbrC "ploidy" phenotype in Escherichia coli.
abstract: The mbrC17 mutation in Escherichia coli had been shown to cause conditional growth defects and an increase in the quantity of DNA per cell. The present work was aimed at identifying the mutation. Sequencing showed that the MbrC17 phenotype does not involve glr (murI), as previously suggested. P1 transduction data indicated that the mbrC17 mutation is closely linked to rpoB, and allele exchange showed it to lie within the secE-nusG operon. A single change relative to wild type was found in the secE-nusG region from the mbrC17 strain, a G-->A mutation 23 bp upstream of the secE coding sequence. This mutation causes a two-fold increase in the concentration of secE-nusG mRNA.
authors.affiliation: Laboratoire de Microbiologie et Génétique Moléculaire, CNRS, Toulouse, France.
authors.forename: A M
authors.initials: AM
authors.lastname: Estévenon
authors.forename: M
authors.initials: M
authors.lastname: Lemonnier
authors.forename: C
authors.initials: C
authors.lastname: Rouquette
authors.forename: D
authors.initials: D
authors.lastname: Lane
mesh_terms: D000591:Amino Acid Isomerases / Q000235:genetics; D002455:Cell Division; D002874:Chromosome Mapping; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D009154:Mutation; D010641:Phenotype; D011003:Ploidies; D013997:Time Factors
chemical_list: D000591:Amino Acid Isomerases; C062292:glutamate racemase