{"doi":"10.1101/2023.08.30.555460","title":"Sm-like protein Rof inhibits transcription termination factor ρ by binding site obstruction and conformational insulation","abstract":"Abstract Transcription termination factor ρ is a hexameric, RNA-dependent NTPase that can adopt active closed-ring and inactive open-ring conformations. The Sm-like protein Rof, a homolog of the RNA chaperone Hfq, inhibits ρ-dependent termination in vivo but recapitulation of this activity in vitro has proven difficult and the precise mode of Rof action is presently unknown. Our electron microscopic structures of ρ-Rof and ρ-RNA complexes show that Rof undergoes pronounced conformational changes to bind ρ at the protomer interfaces, undercutting ρ conformational dynamics associated with ring closure and occluding extended primary RNA-binding sites that are also part of interfaces between ρ and RNA polymerase. Consistently, Rof impedes ρ ring closure, ρ-RNA interactions, and ρ association with transcription elongation complexes. Structure-guided mutagenesis coupled with functional assays confirmed that the observed ρ-Rof interface is required for Rof-mediated inhibition of cell growth and ρ-termination in vitro . Bioinformatic analyses revealed that Rof is restricted to Pseudomonadota and that the ρ-Rof interface is conserved. Genomic contexts of rof differ between Enterobacteriaceae and Vibrionaceae, suggesting distinct modes of Rof regulation. We hypothesize that Rof and other cellular anti-terminators silence ρ under diverse, but yet to be identified, stress conditions when unrestrained transcription termination by ρ would be lethal.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2023,"id":397182,"datarank":0.0,"base_score":0.0,"endowment":0.0,"self_citation_contribution":0.0,"citation_network_contribution":0.0,"self_endowment_contribution":0.0,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":2,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9552,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2023-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1138447,"name":"Mark Finazzo","orcid":"0009-0000-8737-2699","position":1,"is_corresponding":false},{"id":270920,"name":"Tarek Hilal","orcid":"0000-0002-7833-8058","position":2,"is_corresponding":false},{"id":514554,"name":"Bing Wang","orcid":"0000-0003-1265-9526","position":3,"is_corresponding":false},{"id":1172783,"name":"Tim Luca Selinger","orcid":"0009-0001-2374-2686","position":4,"is_corresponding":false},{"id":969260,"name":"Daniela Gjorgjevikj","orcid":"0000-0002-9581-8440","position":5,"is_corresponding":false},{"id":270927,"name":"Irina Artsimovitch","orcid":"0000-0002-8604-0980","position":6,"is_corresponding":false},{"id":270928,"name":"M.C. Wahl","orcid":"0000-0002-2811-5307","position":7,"is_corresponding":false},{"id":270919,"name":"Nelly Said","orcid":"0000-0001-8352-5555","position":0,"is_corresponding":true}],"reference_count":75,"raw_metadata":null,"created_at":"2026-07-19T01:19:35.497854Z","pmid":"37693585","pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}