Related Experiment Video
Updated: Aug 16, 2026

Artificial RNA Polymerase II Elongation Complexes for Dissecting Co-transcriptional RNA Processing Events
Published on: May 13, 2019
Stable DNA opening within open promoter complexes is mediated by the RNA polymerase beta'-jaw domain
Siva R Wigneshweraraj1, Patricia C Burrows, Konstantin Severinov
1Division of Biology, Faculty of Life Sciences, Sir Alexander Fleming Building, Imperial College London, London SW7 2AZ, United Kingdom.
Abstract:
DNA opening for transcription-competent open promoter complex (OC) formation by the bacterial RNA polymerase (RNAP) relies upon a complex network of interactions between the structurally conserved and flexible modules of the catalytic beta and beta'-subunits, RNAP-associated sigma-subunit, and the DNA. Here, we show that one such module, the beta'-jaw, functions to stabilize the OC. In OCs formed by the major sigma70-RNAP, the stabilizing role of the beta'-jaw is not restricted to any particular melted DNA segment. In contrast, in OCs formed by the major variant sigma54-RNAP, the beta'-jaw and a conserved sigma54 regulatory domain co-operate to stabilize the melted DNA segment immediately upstream of the transcription start site. Clearly, regulated communication between the mobile modules of the RNAP and the functional domain(s) of the sigma subunit is required for stable DNA opening.
Related Concept Videos
Bacterial Transcription
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription Initiation
The promoters and enhancers and their accessory proteins allow tight regulation of...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
Bacterial RNA Polymerase
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
The Eukaryotic Promoter Region
The Eukaryotic Promoter Region

