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-Structure paper
Title | Mechanisms of DNA opening revealed in AAA+ transcription complex structures. |
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Journal, issue, pages | Sci Adv, Vol. 8, Issue 51, Page eadd3479, Year 2022 |
Publish date | Dec 21, 2022 |
Authors | Fuzhou Ye / Forson Gao / Xiaojiao Liu / Martin Buck / Xiaodong Zhang / |
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 ...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. |
External links | Sci Adv / PubMed:36542713 / PubMed Central |
Methods | EM (single particle) |
Resolution | 3.4 - 4.5 Å |
Structure data | EMDB-14171, PDB-7qv9: EMDB-14172: CryoEM structure of bacterial transcription intermediate complex mediated by activator protein PspF EMDB-14190, PDB-7qwp: EMDB-14200, PDB-7qxi: EMDB-14206: Cryo-EM structure of RNA polymerase-sigma54 holoenzyme with promoter DNA and transcription activator PspF intermedate complex EMDB-14207: Cryo-EM structure of RNA polymerase-sigma54 holoenzyme with promoter DNA and transcription activator PspF intermedate complex EMDB-14208: Cryo-EM structure of RNA polymerase-sigma54 holoenzyme with promoter DNA and transcription activator PspF intermedate complex |
Chemicals | ChemComp-ADP: ChemComp-AF3: |
Source |
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Keywords | TRANSCRIPTION / RNA polymerase / AAA protein / transcription regulation / cryoEM / Cryo EM / transcription close complex / sigma54 |