Visualization of the movement of the Escherichia coli RNA polymerase along the lac UV5 promoter during the initiation of the transcription.

Three probes have been used to detect changes in the contacts between Escherichia coli RNA polymerase and lac UV5 promoter during the formation of the open complex and the initiation of the transcription. The results presented here show how contacts between the enzyme and the UV5 promoter are modulated concomitantly with steady-state synthesis of ApApUpU. These results suggest a movement of the enzyme during the initiation of the transcription preceding the irreversible translocation into the elongation complex.