EMD-4397

Single-particle
3.7 Å
EMD-4397 Deposition: 02/05/2018
Map released: 04/07/2018
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links

EMD-4397

Cryo-EM structure of bacterial RNA polymerase-sigma54 holoenzyme initial transcribing complex

EMD-4397

Single-particle
3.7 Å
EMD-4397 Deposition: 02/05/2018
Map released: 04/07/2018
Last modified: 15/05/2024
Overview 3D View Sample Experiment Validation Volume Browser Additional data Links
Sample Organism: Escherichia coli K-12, Klebsiella pneumoniae
Sample: Cryo-EM structure of bacterial RNA polymerase-sigma54 holoenzyme initial transcribing complex
Fitted models: 6gfw (Avg. Q-score: 0.372)

Deposition Authors: Glyde R, Ye FZ
Structures of Bacterial RNA Polymerase Complexes Reveal the Mechanism of DNA Loading and Transcription Initiation.
Glyde R, Ye F , Jovanovic M , Kotta-Loizou I , Buck M, Zhang X
(2018) Mol Cell , 70 , 1111 - 1120.e3
PUBMED: 29932903
DOI: doi:10.1016/j.molcel.2018.05.021
ISSN: 1097-4164
ASTM: MOCEFL
Abstract:
Gene transcription is carried out by multi-subunit RNA polymerases (RNAPs). Transcription initiation is a dynamic multi-step process that involves the opening of the double-stranded DNA to form a transcription bubble and delivery of the template strand deep into the RNAP for RNA synthesis. Applying cryoelectron microscopy to a unique transcription system using σ54N), the major bacterial variant sigma factor, we capture a new intermediate state at 4.1 Å where promoter DNA is caught at the entrance of the RNAP cleft. Combining with new structures of the open promoter complex and an initial de novo transcribing complex at 3.4 and 3.7 Å, respectively, our studies reveal the dynamics of DNA loading and mechanism of transcription bubble stabilization that involves coordinated, large-scale conformational changes of the universally conserved features within RNAP and DNA. In addition, our studies reveal a novel mechanism of strand separation by σ54.