title: Different thermal energy requirement for open complex formation by Escherichia coli RNA polymerase at two related promoters.
abstract: We have studied the effect of temperature on transcription initiation in vitro at two related promoters ga/Pcon and ga/P1, which have the same nucleotide sequence around the -10 region and transcription start site, but differ in upstream sequences. One of the promoters, ga/Pcon, carries the consensus -35 hexamer, 5'TTGACA 3', whilst ga/P1 contains a block of 'distortable' upstream sequences that allow promoter function in the absence of a -35 region consensus sequence. RNA polymerase can form complexes with both promoters at a range of temperatures. However, the thermal energy requirement for open complex formation differs: open complexes can form at ga/P1 at low temperatures, whereas ga/Pcon requires higher temperatures. The thermal energy requirement for transcription from preformed open complexes is the same for both promoters.
authors.affiliation: School of Biochemistry, University of Birmingham, UK.
authors.forename: E
authors.initials: E
authors.lastname: Grimes
authors.forename: S
authors.initials: S
authors.lastname: Busby
authors.forename: S
authors.initials: S
authors.lastname: Minchin
mesh_terms: D001483:Base Sequence; D016172:DNA Fingerprinting; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D005690:Galactose / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D013816:Thermodynamics; D014158:Transcription, Genetic
chemical_list: D012321:DNA-Directed RNA Polymerases; D005690:Galactose