{"doi":"10.1002/pro.4537","title":"Selective incorporation of 5‐hydroxytryptophan blocks long range electron transfer in oxalate decarboxylase","abstract":"Oxalate decarboxylase from Bacillus subtilis is a binuclear Mn-dependent acid stress response enzyme that converts the mono-anion of oxalic acid into formate and carbon dioxide in a redox neutral unimolecular disproportionation reaction. A π-stacked tryptophan dimer, W96 and W274, at the interface between two monomer subunits facilitates long-range electron transfer between the two Mn ions and plays an important role in the catalytic mechanism. Substitution of W96 with the unnatural amino acid 5-hydroxytryptophan leads to a persistent EPR signal which can be traced back to the neutral radical of 5-hydroxytryptophan with its hydroxyl proton removed. 5-Hydroxytryptophan acts as a hole sink preventing the formation of Mn(III) at the N-terminal active site and strongly suppresses enzymatic activity. The lower boundary of the standard reduction potential for the active site Mn(II)/Mn(III) couple can therefore be estimated as 740 mV against the normal hydrogen electrode at pH 4, the pH of maximum catalytic efficiency. Our results support the catalytic importance of long-range electron transfer in oxalate decarboxylase while at the same time highlighting the utility of unnatural amino acid incorporation and specifically the use of 5-hydroxytryptophan as an energetic sink for hole hopping to probe electron transfer in redox proteins.","journal":"Protein Science","year":2022,"id":291660,"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":3,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9456,"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":727025,"name":"Alvaro Montoya","orcid":"0000-0003-4985-7323","position":1,"is_corresponding":false},{"id":401706,"name":"Manasi Kamat","orcid":"0000-0002-6031-0794","position":2,"is_corresponding":false},{"id":361327,"name":"Kari B. Basso","orcid":"0000-0003-1268-6655","position":3,"is_corresponding":false},{"id":974920,"name":"James S. Italia","orcid":"0000-0003-2653-5516","position":4,"is_corresponding":false},{"id":117143,"name":"Abhishek Chatterjee","orcid":"0000-0002-6231-5302","position":5,"is_corresponding":false},{"id":974921,"name":"Μαρία Δρόσου","orcid":"0000-0002-4550-710X","position":6,"is_corresponding":false},{"id":974922,"name":"Dimitrios A. Pantazis","orcid":"0000-0002-2146-9065","position":7,"is_corresponding":false},{"id":727027,"name":"Alexander Angerhofer","orcid":"0000-0002-8580-6024","position":8,"is_corresponding":false},{"id":727024,"name":"Anthony J. Pastore","orcid":"0000-0002-7526-8293","position":0,"is_corresponding":true}],"reference_count":80,"raw_metadata":null,"created_at":"2026-07-19T00:30:38.420009Z","pmid":"36482787","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":[]}