7QV9

CryoEM structure of bacterial transcription intermediate complex mediated by activator PspF

Summary for 7QV9

• Entry DOI: 10.2210/pdb7qv9/pdb
• EMDB information: 14171
• Descriptor: DNA-directed RNA polymerase subunit alpha, ALUMINUM FLUORIDE, DNA-directed RNA polymerase subunit beta, ... (10 entities in total)
• Functional Keywords: rna polymerase, aaa protein, transcription regulation, cryoem, transcription
• Biological source: Escherichia coli K-12; More
• Total number of polymer chains: 14
• Total formula weight: 683975.59

Authors

Ye, F.Z.,Zhang, X.D. (deposition date: 2022-01-20, release date: 2022-11-09, Last modification date: 2024-07-17)

Primary citation

Ye, F.,Gao, F.,Liu, X.,Buck, M.,Zhang, X.
Mechanisms of DNA opening revealed in AAA+ transcription complex structures.
Sci Adv, 8:eadd3479-eadd3479, 2022

PubMed Abstract: Gene transcription is carried out by RNA polymerase (RNAP) and requires the conversion of the initial closed promoter complex, where DNA is double stranded, to a transcription-competent open promoter complex, where DNA is opened up. In bacteria, RNAP relies on σ factors for its promoter specificities. Using a special form of sigma factor (σ), which forms a stable closed complex and requires its activator that belongs to the AAA+ ATPases (ATPases associated with diverse cellular activities), we obtained cryo-electron microscopy structures of transcription initiation complexes that reveal a previously unidentified process of DNA melting opening. The σ amino terminus threads through the locally opened up DNA and then becomes enclosed by the AAA+ hexameric ring in the activator-bound intermediate complex. Our structures suggest how ATP hydrolysis by the AAA+ activator could remove the σ inhibition while helping to open up DNA, using σ amino-terminal peptide as a pry bar.

PubMed: 36542713
DOI: 10.1126/sciadv.add3479

Experimental method

ELECTRON MICROSCOPY (3.5 Å)