6PMJ

Sigm28-transcription initiation complex with specific promoter at the state 2

6PMJ の概要

• エントリーDOI: 10.2210/pdb6pmj/pdb
• 関連するPDBエントリー: 6PMI
• EMDBエントリー: 20394 20395
• 分子名称: DNA-directed RNA polymerase subunit alpha, MAGNESIUM ION, DNA-directed RNA polymerase subunit beta, ... (10 entities in total)
• 機能のキーワード: sigma28, transcription initiation complex, rpof, znr domain, transcription
• 由来する生物種: Escherichia coli O157:H7; 詳細
• タンパク質・核酸の鎖数: 9
• 化学式量合計: 452738.92

構造登録者

Liu, B.,Shi, W. (登録日: 2019-07-02, 公開日: 2020-05-13, 最終更新日: 2024-03-20)

主引用文献

Shi, W.,Zhou, W.,Zhang, B.,Huang, S.,Jiang, Y.,Schammel, A.,Hu, Y.,Liu, B.
Structural basis of bacterial sigma28-mediated transcription reveals roles of the RNA polymerase zinc-binding domain.
Embo J., 39:e104389-e104389, 2020

PubMed Abstract: In bacteria, σ is the flagella-specific sigma factor that targets RNA polymerase (RNAP) to control the expression of flagella-related genes involving bacterial motility and chemotaxis. However, the structural mechanism of σ -dependent promoter recognition remains uncharacterized. Here, we report cryo-EM structures of E. coli σ -dependent transcribing complexes on a complete flagella-specific promoter. These structures reveal how σ -RNAP recognizes promoter DNA through strong interactions with the -10 element, but weak contacts with the -35 element, to initiate transcription. In addition, we observed a distinct architecture in which the β' zinc-binding domain (ZBD) of RNAP stretches out from its canonical position to interact with the upstream non-template strand. Further in vitro and in vivo assays demonstrate that this interaction has the overall effect of facilitating closed-to-open isomerization of the RNAP-promoter complex by compensating for the weak interaction between σ4 and -35 element. This suggests that ZBD relocation may be a general mechanism employed by σ family factors to enhance transcription from promoters with weak σ4/-35 element interactions.

PubMed: 32484956
DOI: 10.15252/embj.2020104389

実験手法

ELECTRON MICROSCOPY (3.91 Å)