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-Structure paper
Title | Mycobacterial HelD is a nucleic acids-clearing factor for RNA polymerase. |
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Journal, issue, pages | Nat Commun, Vol. 11, Issue 1, Page 6419, Year 2020 |
Publish date | Dec 18, 2020 |
Authors | Tomáš Kouba / Tomáš Koval' / Petra Sudzinová / Jiří Pospíšil / Barbora Brezovská / Jarmila Hnilicová / Hana Šanderová / Martina Janoušková / Michaela Šiková / Petr Halada / Michal Sýkora / Ivan Barvík / Jiří Nováček / Mária Trundová / Jarmila Dušková / Tereza Skálová / URee Chon / Katsuhiko S Murakami / Jan Dohnálek / Libor Krásný / |
PubMed Abstract | RNA synthesis is central to life, and RNA polymerase (RNAP) depends on accessory factors for recovery from stalled states and adaptation to environmental changes. Here, we investigated the mechanism ...RNA synthesis is central to life, and RNA polymerase (RNAP) depends on accessory factors for recovery from stalled states and adaptation to environmental changes. Here, we investigated the mechanism by which a helicase-like factor HelD recycles RNAP. We report a cryo-EM structure of a complex between the Mycobacterium smegmatis RNAP and HelD. The crescent-shaped HelD simultaneously penetrates deep into two RNAP channels that are responsible for nucleic acids binding and substrate delivery to the active site, thereby locking RNAP in an inactive state. We show that HelD prevents non-specific interactions between RNAP and DNA and dissociates stalled transcription elongation complexes. The liberated RNAP can either stay dormant, sequestered by HelD, or upon HelD release, restart transcription. Our results provide insights into the architecture and regulation of the highly medically-relevant mycobacterial transcription machinery and define HelD as a clearing factor that releases RNAP from nonfunctional complexes with nucleic acids. |
External links | Nat Commun / PubMed:33339823 / PubMed Central |
Methods | EM (single particle) / X-ray diffraction |
Resolution | 2 - 3.36 Å |
Structure data | EMDB-10996, PDB-6yxu: EMDB-11004, PDB-6yys: EMDB-11026, PDB-6z11: PDB-6vsx: |
Chemicals | ChemComp-PO4: ChemComp-HOH: ChemComp-ZN: ChemComp-MG: |
Source |
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Keywords | TRANSCRIPTION / RNA polymerase / Helicase / transcription cycle helicase-like protein RNA polymerase / trasncription / transcription cycle helicase-like protein RNA polymerase transcription |