{"doi":"10.1021/jacs.2c12953","title":"Changing Fates of the Substrate Radicals Generated in the Active Sites of the B<sub>12</sub>-Dependent Radical SAM Enzymes OxsB and AlsB","abstract":"OxsB is a B 12 -dependent radical SAM enzyme that catalyzes the oxidative ring contraction of 2′-deoxyadenosine 5′-phosphate to the dehydrogenated, oxetane containing precursor of oxetanocin A phosphate. AlsB is a homologue of OxsB that participates in a similar reaction during the biosynthesis of albucidin. Herein, OxsB and AlsB are shown to also catalyze radical mediated, stereoselective C2′-methylation of 2′-deoxyadenosine monophosphate. This reaction proceeds with inversion of configuration such that the resulting product also possesses a C2′ hydrogen atom available for abstraction. However, in contrast to methylation, subsequent rounds of catalysis result in C–C dehydrogenation of the newly added methyl group to yield a 2′-methylidene followed by radical addition of a 5′-deoxyadenosyl moiety to produce a heterodimer. These observations expand the scope of reactions catalyzed by B 12 -dependent radical SAM enzymes and emphasize the susceptibility of radical intermediates to bifurcation along different reaction pathways even within the highly organized active site of an enzyme.","journal":"Journal of the American Chemical Society","year":2023,"id":342183,"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":14,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.9505,"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":1079201,"name":"Yu-Cheng Yeh","orcid":null,"position":1,"is_corresponding":false},{"id":1079202,"name":"Po‐Hsun Fan","orcid":null,"position":2,"is_corresponding":false},{"id":864547,"name":"Aoshu Zhong","orcid":"0000-0002-5793-3990","position":3,"is_corresponding":false},{"id":421160,"name":"Mark W. Ruszczycky","orcid":null,"position":4,"is_corresponding":false},{"id":419939,"name":"Hung‐wen Liu","orcid":"0000-0001-8953-4794","position":5,"is_corresponding":false},{"id":975054,"name":"Yu‐Hsuan Lee","orcid":"0009-0005-0915-7172","position":0,"is_corresponding":true}],"reference_count":63,"raw_metadata":null,"created_at":"2026-07-19T01:11:12.506815Z","pmid":"36719327","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":[]}