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Updated: Jul 2, 2026

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
Published on: May 13, 2019
Polymerase II promoter activation: closed complex formation and ATP-driven start site opening
1Department of Chemistry and Biochemistry, University of California, Los Angeles 90024.
Abstract:
Studies on bacterial RNA polymerases have divided the initiation pathway into three steps, namely (i) promoter binding to form the closed complex; (ii) DNA melting to form an open complex, and (iii) messenger RNA initiation. Potassium permanganate was used to detect DNA melting by mammalian RNA polymerase II in vitro. Closed complexes formed in a rate-limiting step that was stimulated by the activator GAL4-VP16. Adenosine triphosphate was then hydrolyzed to rapidly melt the DNA within the closed complex to form an open complex. Addition of nucleoside triphosphates resulted in the melted bubble moving away from the start site, completing initiation.
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