8FIX

Cryo-EM structure of E. coli RNA polymerase backtracked elongation complex harboring a terminal mismatch

8FIX の概要

• エントリーDOI: 10.2210/pdb8fix/pdb
• EMDBエントリー: 29212
• 分子名称: Non-template DNA, Template DNA, DNA-directed RNA polymerase subunit alpha, ... (9 entities in total)
• 機能のキーワード: rna polymerase, ribosome, coupling, transcription
• 由来する生物種: Escherichia coli K-12; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 404867.38

構造登録者

Florez Ariza, A.,Wee, L.,Tong, A.,Canari, C.,Grob, P.,Nogales, E.,Bustamante, C. (登録日: 2022-12-17, 公開日: 2023-03-29, 最終更新日: 2024-06-19)

主引用文献

Wee, L.M.,Tong, A.B.,Florez Ariza, A.J.,Canari-Chumpitaz, C.,Grob, P.,Nogales, E.,Bustamante, C.J.
A trailing ribosome speeds up RNA polymerase at the expense of transcript fidelity via force and allostery.
Cell, 186:1244-1262.e34, 2023

PubMed Abstract: In prokaryotes, translation can occur on mRNA that is being transcribed in a process called coupling. How the ribosome affects the RNA polymerase (RNAP) during coupling is not well understood. Here, we reconstituted the E. coli coupling system and demonstrated that the ribosome can prevent pausing and termination of RNAP and double the overall transcription rate at the expense of fidelity. Moreover, we monitored single RNAPs coupled to ribosomes and show that coupling increases the pause-free velocity of the polymerase and that a mechanical assisting force is sufficient to explain the majority of the effects of coupling. Also, by cryo-EM, we observed that RNAPs with a terminal mismatch adopt a backtracked conformation, while a coupled ribosome allosterically induces these polymerases toward a catalytically active anti-swiveled state. Finally, we demonstrate that prolonged RNAP pausing is detrimental to cell viability, which could be prevented by polymerase reactivation through a coupled ribosome.

PubMed: 36931247
DOI: 10.1016/j.cell.2023.02.008

実験手法

ELECTRON MICROSCOPY (3.9 Å)