6YXU

Structure of Mycobacterium smegmatis HelD protein in complex with RNA polymerase core - State I, primary channel engaged

Summary for 6YXU

• Entry DOI: 10.2210/pdb6yxu/pdb
• EMDB information: 10996
• 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: transcription cycle helicase-like protein rna polymerase, transcription
• Biological source: Mycolicibacterium smegmatis MC2 155; More
• Total number of polymer chains: 6
• Total formula weight: 444309.88

Authors

Kouba, T.,Koval, T.,Krasny, L.,Dohnalek, J. (deposition date: 2020-05-03, release date: 2020-11-04, Last modification date: 2024-05-22)

Primary citation

Kouba, T.,Koval', T.,Sudzinova, P.,Pospisil, J.,Brezovska, B.,Hnilicova, J.,Sanderova, H.,Janouskova, M.,Sikova, M.,Halada, P.,Sykora, M.,Barvik, I.,Novacek, J.,Trundova, M.,Duskova, J.,Skalova, T.,Chon, U.,Murakami, K.S.,Dohnalek, J.,Krasny, L.
Mycobacterial HelD is a nucleic acids-clearing factor for RNA polymerase.
Nat Commun, 11:6419-6419, 2020

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 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.

PubMed: 33339823
DOI: 10.1038/s41467-020-20158-4

Experimental method

ELECTRON MICROSCOPY (3.08 Å)