7QXI

Cryo-EM structure of RNA polymerase-sigma54 holo enzyme with promoter DNA closed complex

Summary for 7QXI

• Entry DOI: 10.2210/pdb7qxi/pdb
• EMDB information: 14190 14200
• Descriptor: DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, DNA-directed RNA polymerase subunit beta', ... (7 entities in total)
• Functional Keywords: cryo em, rna polymerase, transcription close complex, sigma54, transcription
• Biological source: Escherichia coli K-12; More
• Total number of polymer chains: 8
• Total formula weight: 484563.39

Authors

Ye, F.Z.,Zhang, X.D. (deposition date: 2022-01-26, 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 (3.4 Å)