title: Specific activation of transcription initiation by the sequence-specific DNA-binding agents distamycin A and netropsin.
abstract: A series of promoters with nine base-pair substitutions in the spacer DNA separating the -10 and -35 regions was used to demonstrate that Escherichia coli RNA polymerase is sensitive to events affecting the spacer DNA--a region not directly contacted by the enzyme. The drugs distamycin A and netropsin specifically enhanced the rate of functional complex formation at a promoter bearing a substitution of nonalternating A-T base pairs. The effect is exerted at an early step in the RNA polymerase-promoter interaction. We hypothesize that a drug-induced structural alteration in the spacer DNA occurs, similar to that normally resulting from RNA polymerase binding. These findings are relevant to an understanding of potential mechanisms of transcription activation.
mesh_terms: D001483:Base Sequence; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D004214:Distamycins / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology / Q000235:genetics*; D014644:Genetic Variation; D006146:Guanidines / Q000494:pharmacology*; D007700:Kinetics; D009429:Netropsin / Q000494:pharmacology*; D011401:Promoter Regions, Genetic; D011758:Pyrroles / Q000494:pharmacology*; D014158:Transcription, Genetic / Q000187:drug effects*
chemical_list: D004214:Distamycins; D006146:Guanidines; D011758:Pyrroles; D009429:Netropsin; D012321:DNA-Directed RNA Polymerases