RRC ID 3762
著者 Schroeder LA, Gries TJ, Saecker RM, Record MT Jr, Harris ME, DeHaseth PL.
タイトル Evidence for a tyrosine-adenine stacking interaction and for a short-lived open intermediate subsequent to initial binding of Escherichia coli RNA polymerase to promoter DNA.
ジャーナル J Mol Biol
Abstract Bacterial RNA polymerase and a "sigma" transcription factor form an initiation-competent "open" complex at a promoter by disruption of about 14 base pairs. Strand separation is likely initiated at the highly conserved -11 A-T base pair. Amino acids in conserved region 2.3 of the main Escherichia coli sigma factor, sigma(70), are involved in this process, but their roles are unclear. To monitor the fates of particular bases upon addition of RNA polymerase, promoters bearing single substitutions of the fluorescent A-analog 2-aminopurine (2-AP) at -11 and two other positions in promoter DNA were examined. Evidence was obtained for an open intermediate on the pathway to open complex formation, in which these 2-APs are no longer stacked onto their neighboring bases. The tyrosine at residue 430 in region 2.3 of sigma(70) was shown to be involved in quenching the fluorescence of a 2-AP substituted at -11, presumably through a stacking interaction. These data refine the structural model for open complex formation and reveal a novel interaction involved in DNA melting by RNA polymerase.
巻・号 385(2)
ページ 339-49
公開日 2009-1-16
DOI 10.1016/j.jmb.2008.10.023
PII S0022-2836(08)01301-6
PMID 18976666
PMC PMC2677906
MeSH Adenine / metabolism* DNA, Bacterial / metabolism* DNA-Directed RNA Polymerases / metabolism* Escherichia coli / enzymology* Escherichia coli Proteins / metabolism* Promoter Regions, Genetic Protein Binding Sigma Factor / metabolism* Tyrosine / metabolism*
IF 4.76
引用数 35
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
原核生物(大腸菌)