{"doi":"10.1101/2022.03.09.483586","title":"The Anti- <i>Burkholderia</i> Lasso Peptide Ubonodin Co-Opts the Siderophore Receptor PupB for Cellular Entry","abstract":"ABSTRACT New antibiotics are needed as bacterial infections continue to be a leading cause of death. Notorious among antibiotic-resistant bacteria is the Burkholderia cepacia complex (Bcc), which infects cystic fibrosis patients, causing lung function decline. We recently discovered a novel ribosomally synthesized and post-translationally modified peptide (RiPP), ubonodin, with potent activity against several Burkholderia pathogens. Ubonodin inhibits RNA polymerase, but only select Bcc strains were susceptible, indicating that having a conserved cellular target does not guarantee activity. Given the cytoplasmic target, we speculate that cellular uptake of ubonodin determines susceptibility. Here, we report a new outer membrane siderophore receptor, PupB, that is required for ubonodin uptake in B. cepacia . Loss of PupB renders B. cepacia resistant to ubonodin, whereas expressing PupB sensitizes a resistant strain. Thus, outer membrane transport is the major determinant of ubonodin’s spectrum of activity. We also show that PupB is activated by a TonB protein and examine a transcriptional pathway that further regulates PupB. Finally, we elucidate the complete cellular uptake pathway for ubonodin by also identifying its inner membrane transporter in B. cepacia . Our work unravels central steps in the mechanism of action of ubonodin and establishes a general framework for dissecting RiPP function.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2022,"id":306380,"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":0.9568,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2022-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":991234,"name":"Alina Thokkadam","orcid":"0000-0002-7782-4986","position":1,"is_corresponding":false},{"id":473521,"name":"Robert Leach","orcid":"0000-0001-5153-7754","position":2,"is_corresponding":false},{"id":636130,"name":"A. James Link","orcid":"0000-0001-5066-9691","position":3,"is_corresponding":false},{"id":270268,"name":"Truc Do","orcid":"0000-0001-7212-0296","position":0,"is_corresponding":true}],"reference_count":88,"raw_metadata":null,"created_at":"2026-07-19T00:32:48.984902Z","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":[]}