{"id":"a3824eac-8542-5553-9752-afe32ed86641","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-egtb-sulfur-donor","predicate":"couples_sulfur_from","statement":"Mycobacterium thermoresistibile EgtB coupled gamma-glutamylcysteine to hercynine through an oxygen-dependent C-S bond-forming reaction.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"b8aa6891-ca60-5bcb-af86-611242e031e9","mechanism_event_label":"A cysteine-containing precursor supplies sulfur.","subject":{"id":"3ecbb6b4-7262-5242-a218-658961411138","slug":"mycobacterium-thermoresistibile-egtb","display_name":"Mycobacterium thermoresistibile EgtB","entity_type_key":"protein"},"object":{"id":"d47d2006-2fb8-56ea-a76a-7919171f66ce","slug":"gamma-glutamylcysteine","display_name":"Gamma-glutamylcysteine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"b8aa6891-ca60-5bcb-af86-611242e031e9","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-egtb-sulfur-donor-event","event_type":"observed_relationship","label":"A cysteine-containing precursor supplies sulfur.","description":"Mycobacterium thermoresistibile EgtB coupled gamma-glutamylcysteine to hercynine through an oxygen-dependent C-S bond-forming reaction.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"3ecbb6b4-7262-5242-a218-658961411138","slug":"mycobacterium-thermoresistibile-egtb","display_name":"Mycobacterium thermoresistibile EgtB","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d47d2006-2fb8-56ea-a76a-7919171f66ce","slug":"gamma-glutamylcysteine","display_name":"Gamma-glutamylcysteine","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"939c92c3-50ea-5a4a-9654-8e3b94448132","slug":"ergothioneine","display_name":"L-Ergothioneine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"b3583649-cbbd-50f1-be33-26b1ee0dd6ab","slug":"hercynine","display_name":"Hercynine / N-alpha-trimethylhistidine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"8a0617df-cacc-55b1-b5ff-3b28afa12f20","slug":"hercynyl-gamma-glutamylcysteine-sulfoxide","display_name":"Hercynyl-gamma-glutamylcysteine sulfoxide","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"59d6d1cd-df32-5b58-b950-3188bc7b95d6","slug":"iron-ii","display_name":"Ferrous iron","entity_type_key":"ion"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Crystal structure and enzyme mechanism study.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Non-heme iron coordination supports a proposed radical mechanism, not direct observation of every intermediate.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Ergothioneine collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"ergothioneine","display_name":"L-Ergothioneine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A cysteine-containing precursor supplies sulfur.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structure of the sulfoxide synthase EgtB from the ergothioneine biosynthetic pathway. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25597398/ · DOI 10.1002/anie.201410045","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"cc40d8d5-2374-5dea-af8f-8eaa7913789a","evidence_kind":"source_excerpt","locator":"Lines 184-190","start_line":184,"end_line":190,"excerpt":"## ergothioneine-egtb-sulfur-donor\nA cysteine-containing precursor supplies sulfur.\nMycobacterium thermoresistibile EgtB coupled gamma-glutamylcysteine to hercynine through an oxygen-dependent C-S bond-forming reaction.\nModel: Crystal structure and enzyme mechanism study.\nLimitations: Non-heme iron coordination supports a proposed radical mechanism, not direct observation of every intermediate.\nEvidence access: Primary abstract\nStructure of the sulfoxide synthase EgtB from the ergothioneine biosynthetic pathway. · 2015 · https://pubmed.ncbi.nlm.nih.gov/25597398/ · DOI 10.1002/anie.201410045","model_system":"Crystal structure and enzyme mechanism study.","directness":"reported_statement","verification_status":"source_derived_draft","notes":"Original curation paraphrase; evidence access and experimental limitations specified.","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"2f037d98-f3d0-5dbe-80d8-90b738f130d6","stable_key":"import-59b18080-c560-563d-abc5-bac4ee82a27c","title":"Ergothioneine: transport, redox chemistry and cross-nutrient mechanisms (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"b6def8119f03cfabeec2fb55ba924340dc612e1dd42f05404201fa2b7ced5259","revision_id":"f88c38e6-ffb5-5a68-83ca-4610ca2c2df4","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}