Obligatory activator-polymerase addition order at promoters.
The kinetics of open complex formation were measured by migration retardation assay and DNase I footprinting at the activator-dependent promoters ara P1, lac P1 and gal P1. In each case, the rate of open complex formation was significantly faster if the activator, AraC for ara and CAP for lac and gal, had been added before RNA polymerase. The results indicate that complexes of transcriptional activators, RNA polymerase and promoter can exist in two states, one which can form open complexes rapidly and one which cannot.
Zhang
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X
Biology Department, Johns Hopkins University, Baltimore, MD 21218, USA.
Schleif
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R
D051777:AraC Transcription Factor; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D018983:DNA Footprinting; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D007700:Kinetics; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000378:metabolism*; D014157:Transcription Factors; D014158:Transcription, Genetic
D051777:AraC Transcription Factor; D001426:Bacterial Proteins; D002352:Carrier Proteins; D002373:Cyclic AMP Receptor Protein; D012097:Repressor Proteins; D014157:Transcription Factors; D004247:DNA; D012321:DNA-Directed RNA Polymerases; D003850:Deoxyribonuclease I