Bacterial Transcription

o The RNA polymerase core enzyme and sigma subunit bind to —to and —35 Closed promoter Start site promoter consensus r——‘—-1 ‘ Termination sequences. RNA polymerase ' *1 Transcription sequence Coding S' 3‘ Template 3’ 5- -35 —‘| 0 a DNA unwinds near the Start site transcription start site to form l Termination the open promoter complex. sequence Coding 5’ .- I" 3' i Template 3' 5’ —35 -10 Open promoter 9 RNA polymerase holoenzyme initiates transcrip Start site tion and begins RNA synthesis. The sigma subunit 3 Termination dissociates shortly after transcription initiation. *1 Transcription sequence and the core enzyme continues transcription. ‘" A Coding 5' ,. ‘ "ll 3. Template 3’ ‘ ' V 5' 3' 6 RNA 0 The core enzyme synthesizes until it encounters the Start Site termination sequence. As RNA synthesis progresses, the l . . Termination DNA duplex unwinds to allow the template strand to *1 Transcrlptlon sequence direct RNA assembly. The duplex closes following synthesis. Coding 5' , 3' Template 3' 5' 5. e Transcription terminates at the Start site termination sequence, and the core ‘ Termination enzyme and RNA transcript are released. T l sequence Coding 5' , 3‘ Template 3' 5' RNA transcript