8R2M

Mycobacterium smegnatis RNA polymerase transcription initiation complex with SigmaA, RbpA, HelD N-terminal domain and an upstream-fork promoter fragment; State III conformation

8R2M の概要

• エントリーDOI: 10.2210/pdb8r2m/pdb
• 関連するPDBエントリー: 8Q3I
• EMDBエントリー: 18851
• 分子名称: DNA-directed RNA polymerase subunit alpha, ZINC ION, MAGNESIUM ION, ... (11 entities in total)
• 機能のキーワード: held, rna polymerase, transcription initiation, mycobacteria, transcription, rifampicin resistance
• 由来する生物種: Mycolicibacterium smegmatis MC2 155; 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 525212.71

構造登録者

Koval, T.,Krasny, L.,Dohnalek, J.,Kouba, T. (登録日: 2023-11-06, 公開日: 2024-10-02, 最終更新日: 2025-07-02)

主引用文献

Koval, T.,Borah, N.,Sudzinova, P.,Brezovska, B.,Sanderova, H.,Vankova Hausnerova, V.,Krenkova, A.,Hubalek, M.,Trundova, M.,Adamkova, K.,Duskova, J.,Schwarz, M.,Wiedermannova, J.,Dohnalek, J.,Krasny, L.,Kouba, T.
Mycobacterial HelD connects RNA polymerase recycling with transcription initiation.
Nat Commun, 15:8740-8740, 2024

PubMed Abstract: Mycobacterial HelD is a transcription factor that recycles stalled RNAP by dissociating it from nucleic acids and, if present, from the antibiotic rifampicin. The rescued RNAP, however, must disengage from HelD to participate in subsequent rounds of transcription. The mechanism of release is unknown. We show that HelD from Mycobacterium smegmatis forms a complex with RNAP associated with the primary sigma factor σ and transcription factor RbpA but not CarD. We solve several structures of RNAP-σ-RbpA-HelD without and with promoter DNA. These snapshots capture HelD during transcription initiation, describing mechanistic aspects of HelD release from RNAP and its protective effect against rifampicin. Biochemical evidence supports these findings, defines the role of ATP binding and hydrolysis by HelD in the process, and confirms the rifampicin-protective effect of HelD. Collectively, these results show that when HelD is present during transcription initiation, the process is protected from rifampicin until the last possible moment.

PubMed: 39384756
DOI: 10.1038/s41467-024-52891-5

実験手法

ELECTRON MICROSCOPY (3.44 Å)