6K4Y

CryoEM structure of sigma appropriation complex

6K4Y の概要

• エントリーDOI: 10.2210/pdb6k4y/pdb
• EMDBエントリー: 9916
• 分子名称: DNA-directed RNA polymerase subunit alpha, MAGNESIUM ION, ZINC ION, ... (11 entities in total)
• 機能のキーワード: rna polymerase, sigma appropriation, transcription activation, promoter, transcription
• 由来する生物種: Escherichia coli K-12; 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 533593.50

構造登録者

Shi, J.,Wen, A.,Feng, Y. (登録日: 2019-05-27, 公開日: 2019-08-07, 最終更新日: 2024-03-27)

主引用文献

Shi, J.,Wen, A.,Zhao, M.,You, L.,Zhang, Y.,Feng, Y.
Structural basis of sigma appropriation.
Nucleic Acids Res., 47:9423-9432, 2019

PubMed Abstract: Bacteriophage T4 middle promoters are activated through a process called σ appropriation, which requires the concerted effort of two T4-encoded transcription factors: AsiA and MotA. Despite extensive biochemical and genetic analyses, puzzle remains, in part, because of a lack of precise structural information for σ appropriation complex. Here, we report a single-particle cryo-electron microscopy (cryo-EM) structure of an intact σ appropriation complex, comprising AsiA, MotA, Escherichia coli RNA polymerase (RNAP), σ70 and a T4 middle promoter. As expected, AsiA binds to and remodels σ region 4 to prevent its contact with host promoters. Unexpectedly, AsiA undergoes a large conformational change, takes over the job of σ region 4 and provides an anchor point for the upstream double-stranded DNA. Because σ region 4 is conserved among bacteria, other transcription factors may use the same strategy to alter the landscape of transcription immediately. Together, the structure provides a foundation for understanding σ appropriation and transcription activation.

PubMed: 31392983
DOI: 10.1093/nar/gkz682

実験手法

ELECTRON MICROSCOPY (3.79 Å)