Probing the Structure of the Dynamic Initial Transcribing Complexes on Escherichia Coli Promoters

Transcription is the process by which the RNA polymerase binds to the DNA template and synthesizes RNA. This process is further divided into initiation, elongation and termination phases. During transcription initiation, the RNA polymerase (R) recognizes and binds to the promoter DNA (P) to form the closed complex, RPc. The double-stranded promoter DNA is then melted into single stranded transcription bubble, resulting in the open promoter-polymerase complex, RPo. Subsequently, in the presence of nucleotide substrate, the RNA Polymerase undergoes several rounds of abortive initiation before escaping from the promoter region. Thus, the abortive initiationpromoter escape reactions connect the initiation and elongation phases.