{"doi":"10.1101/2021.04.01.438105","title":"Monitoring iron-sulfur cluster occupancy across the <i>E. coli</i> proteome using chemoproteomics","abstract":"Abstract Iron-sulfur (Fe-S) clusters are ubiquitous metallocofactors found across diverse protein families, where they perform myriad functions including redox chemistry, radical generation, and gene regulation. Monitoring Fe-S cluster occupancy in protein targets directly within native biological systems has been challenging. Commonly utilized spectroscopic methods to detect Fe-S clusters require purification of proteins prior to analysis. Global iron incorporation into the proteome can be monitored using radiolabeled iron, but limitations include the low resolution afforded by gel-based autoradiography. Here, we report the development of a mass spectrometry-based strategy to assess Fe-S cluster binding in a native proteome. This chemoproteomic strategy relies on monitoring changes in the reactivity of Fe-S cluster cysteine ligands upon disruption of Fe-S cluster incorporation. Application to E. coli cells cultured under iron-depleted conditions enabled monitoring of disruptions to Fe-S cluster incorporation broadly across the E. coli Fe-S proteome. Evaluation of E. coli deletion strains of three scaffold proteins within the Isc Fe-S biogenesis pathway enabled the identification of Fe-S clients that are reliant on each individual scaffold protein for proper cluster installation. Lastly, cysteine-reactivity changes characteristic of Fe-S ligands were used to identify previously unannotated Fe-S proteins, including the tRNA hydroxylase, TrhP, and a member of a family of membrane transporter ATPase subunits, DppD. In summary, the chemoproteomic strategy described herein provides a powerful tool to report on Fe-S cluster incorporation directly within a native proteome, to interrogate the role of scaffold and accessory proteins within Fe-S biogenesis pathways, and to identify previously uncharacterized Fe-S proteins.","journal":"bioRxiv (Cold Spring Harbor Laboratory)","year":2021,"id":216482,"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":4,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9601,"is_data_producer":false,"deposit_databanks":null,"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":135937,"name":"Eranthie Weerapana","orcid":"0000-0002-0835-8301","position":1,"is_corresponding":false},{"id":455048,"name":"Daniel W. Bak","orcid":"0000-0002-2252-1718","position":0,"is_corresponding":true}],"reference_count":52,"raw_metadata":null,"created_at":"2026-07-18T23:53:11.245932Z","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":[]}