8JO2

Structural basis of transcriptional activation by the OmpR/PhoB-family response regulator PmrA

8JO2 の概要

• エントリーDOI: 10.2210/pdb8jo2/pdb
• EMDBエントリー: 36453
• 分子名称: DNA (65-MER), DNA-directed RNA polymerase subunit alpha, DNA-directed RNA polymerase subunit beta, ... (8 entities in total)
• 機能のキーワード: pmra, rna polymerase, cryo-em, transcription
• 由来する生物種: Escherichia coli BL21(DE3); 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 550996.69

構造登録者

Lou, Y.-C.,Huang, H.-Y.,Chen, C.,Wu, K.-P. (登録日: 2023-06-06, 公開日: 2023-08-30, 最終更新日: 2023-10-25)

主引用文献

Lou, Y.C.,Huang, H.Y.,Yeh, H.H.,Chiang, W.H.,Chen, C.,Wu, K.P.
Structural basis of transcriptional activation by the OmpR/PhoB-family response regulator PmrA.
Nucleic Acids Res., 51:10049-10058, 2023

PubMed Abstract: PmrA, an OmpR/PhoB-family response regulator, triggers gene transcription responsible for polymyxin resistance in bacteria by recognizing promoters where the canonical-35 element is replaced by the pmra-box, representing the PmrA recognition sequence. Here, we report a cryo-electron microscopy (cryo-EM) structure of a bacterial PmrA-dependent transcription activation complex (TAC) containing a PmrA dimer, an RNA polymerase σ70 holoenzyme (RNAPH) and the pbgP promoter DNA. Our structure reveals that the RNAPH mainly contacts the PmrA C-terminal DNA-binding domain (DBD) via electrostatic interactions and reorients the DBD three base pairs upstream of the pmra-box, resulting in a dynamic TAC conformation. In vivo assays show that the substitution of the DNA-recognition residue eliminated its transcriptional activity, while variants with altered RNAPH-interacting residues resulted in enhanced transcriptional activity. Our findings suggest that both PmrA recognition-induced DNA distortion and PmrA promoter escape play crucial roles in its transcriptional activation.

PubMed: 37665001
DOI: 10.1093/nar/gkad724

実験手法

ELECTRON MICROSCOPY (2.74 Å)