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Publication Abstract from PubMed

Bacterial RNA helicase rho is a genome sentinel that terminates synthesis of damaged and junk RNAs that are not translated by the ribosome. Co-transcriptional RNA surveillance by rho is essential for quality control of the transcriptome during optimal growth. However, it is unclear how bacteria protect their RNAs from overzealous rho 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 Escherichia coli rho. Our results demonstrate that nucleotides bound at subunit interfaces control rho 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 rho through hyper-oligomerization is a regulatory strategy shared by RNA polymerases, ribosomes, and metabolic enzymes across all life.

Transcription termination factor rho polymerizes under stress.,Wang B, Said N, Hilal T, Finazzo M, Wahl MC, Artsimovitch I bioRxiv [Preprint]. 2023 Aug 18:2023.08.18.553922. doi: , 10.1101/2023.08.18.553922. PMID:37645988^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.