title: In vivo supercoiling of plasmid and chromosomal DNA in an Escherichia coli hns mutant.
abstract: We have used trimethylpsoralen to measure localized levels of unconstrained DNA supercoiling in vivo. The data provide direct evidence that plasmid and chromosomal DNA supercoiling is altered in vivo in an hns mutant. This increase in supercoiling is independent of transcription or changes in the activity of topoisomerase I. These data have implications for the mechanisms by which the chromatin-associated protein H-NS may influence chromosome organization and gene expression.
authors.affiliation: Nuffield Department of Clinical Biochemistry, Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, United Kingdom.
authors.forename: F J
authors.initials: FJ
authors.lastname: Mojica
authors.forename: C F
authors.initials: CF
authors.lastname: Higgins
mesh_terms: D003432:Cross-Linking Reagents; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D009154:Mutation; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000235:genetics*
chemical_list: D003432:Cross-Linking Reagents; D004269:DNA, Bacterial