{"doi":"10.17615/k1hp-as05","title":"Interfering with nucleotide excision by the coronavirus 3′-to-5′ exoribonuclease","abstract":"Some of the most efficacious antiviral therapeutics are ribonucleos(t)ide analogs. The presence of a 3′-to-5′ proofreading exoribonuclease (ExoN) in coronaviruses diminishes the potency of many ribonucleotide analogs. The ability to interfere with ExoN activity will create new possibilities for control of SARS-CoV-2 infection. ExoN is formed by a 1:1 complex of nsp14 and nsp10 proteins. We have purified and characterized ExoN using a robust, quantitative system that reveals determinants of specificity and efficiency of hydrolysis. Double-stranded RNA is preferred over single-stranded RNA. Nucleotide excision is distributive, with only one or two nucleotides hydrolyzed in a single binding event. The composition of the terminal basepair modulates excision. A stalled SARS-CoV-2 replicase in complex with either correctly or incorrectly terminated products prevents excision, suggesting that a mispaired end is insufficient to displace the replicase. Finally, we have discovered several modifications to the 3′-RNA terminus that interfere with or block ExoN-catalyzed excision. While a 3′-OH facilitates hydrolysis of a nucleotide with a normal ribose configuration, this substituent is not required for a nucleotide with a planar ribose configuration such as that present in the antiviral nucleotide produced by viperin. Design of ExoN-resistant, antiviral ribonucleotides should be feasible.","journal":"UNC Libraries","year":2023,"id":402230,"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":0,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9625,"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":526697,"name":"Thomas K. Anderson","orcid":"0000-0002-8076-3985","position":1,"is_corresponding":false},{"id":105123,"name":"Joy Y. Feng","orcid":"0000-0003-4837-1911","position":2,"is_corresponding":false},{"id":574438,"name":"Pankaj Srivastava","orcid":"0000-0001-8677-0804","position":3,"is_corresponding":false},{"id":903264,"name":"Rukesh Chinthapatla","orcid":null,"position":4,"is_corresponding":false},{"id":902653,"name":"Kellan T. Passow","orcid":"0009-0000-6626-7187","position":5,"is_corresponding":false},{"id":337330,"name":"David Dulin","orcid":"0000-0003-4209-0377","position":6,"is_corresponding":false},{"id":802633,"name":"Mohamad S. Sotoudegan","orcid":"0000-0002-1293-8739","position":7,"is_corresponding":false},{"id":463164,"name":"Ibrahim M. Moustafa","orcid":"0000-0002-5122-7569","position":8,"is_corresponding":false},{"id":458585,"name":"Daniel A. Harki","orcid":"0000-0001-5950-931X","position":9,"is_corresponding":false},{"id":787412,"name":"Ramkumar Moorthy","orcid":null,"position":10,"is_corresponding":false},{"id":337326,"name":"Jamie J. Arnold","orcid":"0000-0002-2345-9776","position":11,"is_corresponding":false},{"id":786881,"name":"Samantha A. Kennelly","orcid":"0000-0001-7908-1349","position":12,"is_corresponding":false},{"id":555983,"name":"Craig E. Cameron","orcid":"0000-0002-7564-5642","position":13,"is_corresponding":false},{"id":279924,"name":"Robert N. Kirchdoerfer","orcid":null,"position":0,"is_corresponding":true}],"reference_count":0,"raw_metadata":null,"created_at":"2026-07-19T01:20:23.920156Z","pmid":null,"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":[]}