title: Effect of bacteria growth temperature on the distribution of supercoiled DNA and its thermal stability.
abstract: Changes in DNA supercoiling might be essential to generate the response of cellular machinery to temperature stress. The heat-induced structural transition for a topoisomer depends on the value of its specific linking difference. We detect only less negatively supercoiled DNA and an abundance of alternative irregular DNA forms at culture temperatures close to the growth limit of Escherichia coli. We show that the irregular forms are derived from regular plasmid DNAs and their population in the cells is temperature-dependent. Here, we show that it is possible to isolate and characterize individual DNA topoisomers directly from cells without a topoisomerase treatment. Temperature gradient gel electrophoresis (TGGE) and atomic force microscopy (AFM) were used to study the effect of bacteria growth temperature on the distribution of supercoiled DNA and its thermal stability.
authors.affiliation: Department of Biochemistry, Faculty of Sciences, P. J. Sárik University, Kosice, Kosice, Slovakia.
authors.forename: Jozef
authors.initials: J
authors.lastname: Adamcík
authors.forename: Viktor
authors.initials: V
authors.lastname: Víglaský
authors.forename: Francesco
authors.initials: F
authors.lastname: Valle
authors.forename: Marián
authors.initials: M
authors.lastname: Antalík
authors.forename: Dusan
authors.initials: D
authors.lastname: Podhradský
authors.forename: Giovanni
authors.initials: G
authors.lastname: Dietler
mesh_terms: D001419:Bacteria / Q000235:genetics* / Q000254:growth & development*; D004269:DNA, Bacterial / Q000737:chemistry; D004278:DNA, Superhelical / Q000737:chemistry*; D004587:Electrophoresis, Agar Gel; D015180:Electrophoresis, Gel, Two-Dimensional; D018625:Microscopy, Atomic Force; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics
chemical_list: D004269:DNA, Bacterial; D004278:DNA, Superhelical