6TQO

rrn anti-termination complex

Summary for 6TQO

• Entry DOI: 10.2210/pdb6tqo/pdb
• EMDB information: 10548
• Descriptor: Inositol monophosphatase, DNA-directed RNA polymerase subunit beta', 30S ribosomal protein S4, ... (16 entities in total)
• Functional Keywords: rrn, anti-termination complex, rnap, nus factors, suhb, s4, transcription
• Biological source: Escherichia coli; More
• Total number of polymer chains: 15
• Total formula weight: 626003.20

Authors

Huang, Y.H.,Wahl, M.C.,Loll, B.,Hilal, T.,Said, N. (deposition date: 2019-12-17, release date: 2020-08-05, Last modification date: 2024-05-15)

Primary citation

Huang, Y.H.,Hilal, T.,Loll, B.,Burger, J.,Mielke, T.,Bottcher, C.,Said, N.,Wahl, M.C.
Structure-Based Mechanisms of a Molecular RNA Polymerase/Chaperone Machine Required for Ribosome Biosynthesis.
Mol.Cell, 79:1024-1036.e5, 2020

PubMed 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.

PubMed: 32871103
DOI: 10.1016/j.molcel.2020.08.010

Experimental method

ELECTRON MICROSCOPY (3.8 Å)