In: Chemistry
In transcription what is the open complex?
Open complex formation during transcription initiation at the Escherichia coli galP1 promoter.
The temperature requirement for open complex formation was used as an indication of the kinetics of this process.
DNase I footprinting has been used to reveal the structure of open promoter complexes and the temperature requirement for open complex formation has been determined using potassium permanganate as a probe
a question of how the open complex is formed still remains open, and several qualitative hypotheses for opening of DNA by RNAP have been proposed
Transcription by RNAP consists of transcription initiation, elongation, and termination. Transcription initiation is both the first step and a major point in regulation of gene expression. For promoter-directed transcription initiation, the RNAP core must make a complex with a σ-subunit to form the RNAP holoenzyme . Transcription initiation involves binding of the RNAP holoenzyme to double-stranded (ds) DNA, subsequent promoter melting, abortive transcription initiation, and promoter clearance