title: DNA supercoiling allows enhancer action over a large distance.
abstract: Enhancers are regulatory DNA elements that can activate their genomic targets over a large distance. The mechanism of enhancer action over large distance is unknown. Activation of the glnAp2 promoter by NtrC-dependent enhancer in Escherichia coli was analyzed by using a purified system supporting multiple-round transcription in vitro. The data suggest that DNA supercoiling is an essential requirement for enhancer action over a large distance (2,500 bp) but not over a short distance (110 bp). DNA supercoiling facilitates functional enhancer-promoter communication over a large distance, probably by bringing the enhancer and promoter into close proximity.
authors.affiliation: Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, 540 East Canfield Avenue, Room 5123, Detroit, MI 48201, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Liu
authors.forename: V
authors.initials: V
authors.lastname: Bondarenko
authors.forename: A
authors.initials: A
authors.lastname: Ninfa
authors.forename: V M
authors.initials: VM
authors.lastname: Studitsky
mesh_terms: D001483:Base Sequence; D017931:DNA Primers; D004278:DNA, Superhelical / Q000502:physiology*; D004742:Enhancer Elements, Genetic; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D011401:Promoter Regions, Genetic; D014158:Transcription, Genetic
chemical_list: D017931:DNA Primers; D004278:DNA, Superhelical