Kinetics and Mechanism of E. Coli Transcription Initiation

Abstract

In transcription initiation, specific contacts between RNA polymerase (RNAP) and promoter DNA are disrupted as the RNA-DNA hybrid advances into the cleft, resulting in promoter escape of RNAP. From the pattern of large and small rate constants for steps of initiation at λPR promoter at 19°C, we proposed that in-cleft interactions are disrupted in extending 3-mer to 5-mer RNA, −10 interactions are disrupted in extending 6-mer to 9-mer, and −35 interactions are disrupted in extending 10-mer to 11-mer, allowing RNAP to escape.