EMD-10546
bacterial RNA polymerase rrnTAC delta S4 (state 1)
EMD-10546
Single-particle3.8 Å
![EMD-10546](https://www.ebi.ac.uk/emdb/images/entry/EMD-10546/400_10546.gif)
Map released: 16/12/2020
Last modified: 14/04/2021
Sample Organism:
Escherichia coli
Sample: bacterial rRNA transcription anti-termination complex
Deposition Authors: Hilal T, Huang Y, Wahl MC
Sample: bacterial rRNA transcription anti-termination complex
Deposition Authors: Hilal T, Huang Y, Wahl MC
Structure-Based Mechanisms of a Molecular RNA Polymerase/Chaperone Machine Required for Ribosome Biosynthesis.
Huang YH,
Hilal T
,
Loll B
,
Burger J
,
Mielke T,
Bottcher C,
Said N,
Wahl MC
(2020) Mol. Cell , 79 , 1024 - 1036.e5
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
![](http://www.ebi.ac.uk/web_guidelines/images/logos/orcid/orcid_16x16.png)
(2020) Mol. Cell , 79 , 1024 - 1036.e5
Abstract:
Bacterial ribosomal RNAs are synthesized by a dedicated, conserved transcription-elongation complex that transcribes at high rates, shields RNA polymerase from premature termination, and supports co-transcriptional RNA folding, modification, processing, and ribosomal subunit assembly by presently unknown mechanisms. We have determined cryo-electron microscopy structures of complete Escherichia coli ribosomal RNA transcription elongation complexes, comprising RNA polymerase; DNA; RNA bearing an N-utilization-site-like anti-termination element; Nus factors A, B, E, and G; inositol mono-phosphatase SuhB; and ribosomal protein S4. Our structures and structure-informed functional analyses show that fast transcription and anti-termination involve suppression of NusA-stabilized pausing, enhancement of NusG-mediated anti-backtracking, sequestration of the NusG C-terminal domain from termination factor ρ, and the ρ blockade. Strikingly, the factors form a composite RNA chaperone around the RNA polymerase RNA-exit tunnel, which supports co-transcriptional RNA folding and annealing of distal RNA regions. Our work reveals a polymerase/chaperone machine required for biosynthesis of functional ribosomes.
Bacterial ribosomal RNAs are synthesized by a dedicated, conserved transcription-elongation complex that transcribes at high rates, shields RNA polymerase from premature termination, and supports co-transcriptional RNA folding, modification, processing, and ribosomal subunit assembly by presently unknown mechanisms. We have determined cryo-electron microscopy structures of complete Escherichia coli ribosomal RNA transcription elongation complexes, comprising RNA polymerase; DNA; RNA bearing an N-utilization-site-like anti-termination element; Nus factors A, B, E, and G; inositol mono-phosphatase SuhB; and ribosomal protein S4. Our structures and structure-informed functional analyses show that fast transcription and anti-termination involve suppression of NusA-stabilized pausing, enhancement of NusG-mediated anti-backtracking, sequestration of the NusG C-terminal domain from termination factor ρ, and the ρ blockade. Strikingly, the factors form a composite RNA chaperone around the RNA polymerase RNA-exit tunnel, which supports co-transcriptional RNA folding and annealing of distal RNA regions. Our work reveals a polymerase/chaperone machine required for biosynthesis of functional ribosomes.