8Q3O

Bacterial transcription termination factor Rho + pppGpp

This is a non-PDB format compatible entry.

Summary for 8Q3O

• Entry DOI: 10.2210/pdb8q3o/pdb
• Related: 8Q3N
• EMDB information: 18131
• Descriptor: Transcription termination factor Rho, guanosine 5'-(tetrahydrogen triphosphate) 3'-(trihydrogen diphosphate), MAGNESIUM ION (3 entities in total)
• Functional Keywords: rho, termination, transcription
• Biological source: Escherichia coli
• Total number of polymer chains: 6
• Total formula weight: 285177.87

Authors

Said, N.,Hilal, T.,Wahl, M.C. (deposition date: 2023-08-04, release date: 2023-09-27)

Primary citation

Wang, B.,Said, N.,Hilal, T.,Finazzo, M.,Wahl, M.C.,Artsimovitch, I.
Transcription termination factor rho polymerizes under stress.
Biorxiv, 2023

PubMed Abstract: Bacterial RNA helicase ρ is a genome sentinel that terminates synthesis of damaged and junk RNAs that are not translated by the ribosome. Co-transcriptional RNA surveillance by ρ is essential for quality control of the transcriptome during optimal growth. However, it is unclear how bacteria protect their RNAs from overzealous ρ during dormancy or stress, conditions common in natural habitats. Here we used cryogenic electron microscopy, biochemical, and genetic approaches to show that residue substitutions, ADP, or ppGpp promote hyper-oligomerization of ρ. Our results demonstrate that nucleotides bound at subunit interfaces control ρ switching from active hexamers to inactive higher-order oligomers and extended filaments. Polymers formed upon exposure to antibiotics or ppGpp disassemble when stress is relieved, thereby directly linking termination activity to cellular physiology. Inactivation of ρ through hyper-oligomerization is a regulatory strategy shared by RNA polymerases, ribosomes, and metabolic enzymes across all life.

PubMed: 37645988
DOI: 10.1101/2023.08.18.553922

Experimental method

ELECTRON MICROSCOPY (3 Å)