title: Plasmid DNA supercoiling and gyrase activity in Escherichia coli wild-type and rpoS stationary-phase cells.
abstract: Stationary-phase cells displayed a distribution of relaxed plasmids and had the ability to recover plasmid supercoiling as soon as nutrients became available. Preexisting gyrase molecules in these cells were responsible for this recovery. Stationary-phase rpoS cells showed a bimodal distribution of plasmids and failed to supercoil plasmids after the addition of nutrients, suggesting that rpoS plays a role in the regulation of plasmid topology during the stationary phase.
authors.affiliation: Departamento de Biología Molecular y Biotecnología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04510 Mexico, D.F., Mexico.
authors.forename: Yazmid
authors.initials: Y
authors.lastname: Reyes-Domínguez
authors.forename: Gabriel
authors.initials: G
authors.lastname: Contreras-Ferrat
authors.forename: Jesús
authors.initials: J
authors.lastname: Ramírez-Santos
authors.forename: Jorge
authors.initials: J
authors.lastname: Membrillo-Hernández
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Gómez-Eichelmann
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D027081:DNA Gyrase / Q000378:metabolism*; D004278:DNA, Superhelical / Q000737:chemistry*; D004926:Escherichia coli / Q000235:genetics*; D006863:Hydrogen-Ion Concentration; D008025:Ligases / Q000502:physiology; D010957:Plasmids / Q000235:genetics*; D012808:Sigma Factor / Q000502:physiology*; D014158:Transcription, Genetic
chemical_list: D001426:Bacterial Proteins; D004278:DNA, Superhelical; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; D027081:DNA Gyrase; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases