{"id":"a1133124-9c6e-54d6-9342-34da4c21f53b","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-histidine-methylation","predicate":"methylates","statement":"Reconstituted Mycobacterium smegmatis biosynthesis used a methyltransferase to add three methyl groups to the histidine alpha-amino group, producing hercynine.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"c4d1d8f1-63eb-58af-99ca-d3d989577c28","mechanism_event_label":"Microbes first modify histidine before adding sulfur.","subject":{"id":"cae59e2e-148f-5889-82fc-fb3d6632b719","slug":"mycobacterium-smegmatis-egtd","display_name":"Mycobacterium smegmatis EgtD","entity_type_key":"protein"},"object":{"id":"44374451-3436-5136-a8ae-5dcc6d8c353b","slug":"histidine","display_name":"L-Histidine","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"c4d1d8f1-63eb-58af-99ca-d3d989577c28","stable_key":"59b18080-c560-563d-abc5-bac4ee82a27c:ergothioneine-histidine-methylation-event","event_type":"observed_relationship","label":"Microbes first modify histidine before adding sulfur.","description":"Reconstituted Mycobacterium smegmatis biosynthesis used a methyltransferase to add three methyl groups to the histidine alpha-amino group, producing hercynine.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"cae59e2e-148f-5889-82fc-fb3d6632b719","slug":"mycobacterium-smegmatis-egtd","display_name":"Mycobacterium smegmatis EgtD","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"44374451-3436-5136-a8ae-5dcc6d8c353b","slug":"histidine","display_name":"L-Histidine","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":"825f2da2-01bc-5874-a3c6-64f5ac867db5","slug":"s-adenosylmethionine","display_name":"S-Adenosyl-L-methionine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant bacterial enzyme pathway.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Humans have no established equivalent ergothioneine biosynthetic pathway.","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":"Microbes first modify histidine before adding sulfur.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"In vitro reconstitution of Mycobacterial ergothioneine biosynthesis. · 2010 · https://pubmed.ncbi.nlm.nih.gov/20420449/ · DOI 10.1021/ja101721e","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"4659262b-0816-5012-b065-158ff9a71589","evidence_kind":"source_excerpt","locator":"Lines 168-174","start_line":168,"end_line":174,"excerpt":"## ergothioneine-histidine-methylation\nMicrobes first modify histidine before adding sulfur.\nReconstituted Mycobacterium smegmatis biosynthesis used a methyltransferase to add three methyl groups to the histidine alpha-amino group, producing hercynine.\nModel: Recombinant bacterial enzyme pathway.\nLimitations: Humans have no established equivalent ergothioneine biosynthetic pathway.\nEvidence access: Primary abstract\nIn vitro reconstitution of Mycobacterial ergothioneine biosynthesis. · 2010 · https://pubmed.ncbi.nlm.nih.gov/20420449/ · DOI 10.1021/ja101721e","model_system":"Recombinant bacterial enzyme pathway.","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}