{"id":"46521abd-0c7f-58cf-b17b-b233b6df03bc","stable_key":"1acdb1e8-2159-5c7f-b39f-0153ff8024ae:taurine-mto1-gtpbp3","predicate":"with_gtpbp3_forms","statement":"Reconstituting the human MTO1-GTPBP3 complex with hypomodified mitochondrial tRNA, taurine and 5,10-methylene-THF produced the taurine-containing U34 modification.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"1d92084f-8165-53e8-8f27-fa5264cd7fe9","mechanism_event_label":"Two proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA.","subject":{"id":"e4ce9b58-a2a4-5ec2-a449-c529c360fb32","slug":"mto1","display_name":"Human mitochondrial tRNA modification protein / MTO1","entity_type_key":"protein"},"object":{"id":"dd968147-5f93-56d5-bc83-7fa01f9b0e42","slug":"mt-trna-taurinomethyluridine","display_name":"Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34","entity_type_key":"rna_modification"},"evidence_count":1,"mechanism_event":{"id":"1d92084f-8165-53e8-8f27-fa5264cd7fe9","stable_key":"1acdb1e8-2159-5c7f-b39f-0153ff8024ae:taurine-mto1-gtpbp3-event","event_type":"observed_relationship","label":"Two proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA.","description":"Reconstituting the human MTO1-GTPBP3 complex with hypomodified mitochondrial tRNA, taurine and 5,10-methylene-THF produced the taurine-containing U34 modification.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"e4ce9b58-a2a4-5ec2-a449-c529c360fb32","slug":"mto1","display_name":"Human mitochondrial tRNA modification protein / MTO1","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"dd968147-5f93-56d5-bc83-7fa01f9b0e42","slug":"mt-trna-taurinomethyluridine","display_name":"Mitochondrial tRNA 5-taurinomethyluridine / tau-m5U34","entity_type_key":"rna_modification"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"cd2a6b5d-a6cf-5829-b0e4-b52a0f92d153","slug":"gtpbp3","display_name":"Human mitochondrial GTP-binding protein 3 / GTPBP3","entity_type_key":"protein"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"e423cd36-f183-522b-a5e4-5f9ef50eee7e","slug":"taurine","display_name":"Taurine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"0413b195-325e-5757-a72b-f445d65c17bc","slug":"5-10-methylenetetrahydrofolate","display_name":"5,10-Methylenetetrahydrofolate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"c8ccc03a-29cc-5127-baf5-81eeb92ac780","slug":"gtp","display_name":"Guanosine triphosphate","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"evidence_access","value_text":"Primary full text, in-vitro reconstitution methods and results","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human enzyme-complex reconstitution and mass spectrometry.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The reaction mixture also contained GTP, ATP, FAD, NADH, NADPH and magnesium; their presence alone does not demonstrate each is individually limiting.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Taurine collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"taurine","display_name":"Taurine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Two proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Metabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"0326b807-48e0-5045-81a2-2fa305d45334","evidence_kind":"source_excerpt","locator":"Lines 201-207","start_line":201,"end_line":207,"excerpt":"## taurine-mto1-gtpbp3\nTwo proteins join taurine and a folate-derived carbon unit onto mitochondrial tRNA.\nReconstituting the human MTO1-GTPBP3 complex with hypomodified mitochondrial tRNA, taurine and 5,10-methylene-THF produced the taurine-containing U34 modification.\nModel: Human enzyme-complex reconstitution and mass spectrometry.\nLimitations: The reaction mixture also contained GTP, ATP, FAD, NADH, NADPH and magnesium; their presence alone does not demonstrate each is individually limiting.\nEvidence access: Primary full text, in-vitro reconstitution methods and results\nMetabolic and chemical regulation of tRNA modification associated with taurine deficiency and human disease. · 2018 · https://pubmed.ncbi.nlm.nih.gov/29390138/ · DOI 10.1093/nar/gky068","model_system":"Human enzyme-complex reconstitution and mass spectrometry.","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":"dc8d9ab8-fdf9-5107-877c-336cf8005097","stable_key":"import-1acdb1e8-2159-5c7f-b39f-0153ff8024ae","title":"Taurine: synthesis, transport, mitochondrial decoding and nutrient interactions (2026-09-19)","document_type":"imported_text","citation_label":"AI-assisted research curation; primary-abstract references and experimental limitations individually identified. Not publisher full text.","file_path":"","sha256":"c6cb77619a374d9b1b04830032fdd3b33d269d160df5baba3778fad5adf57db5","revision_id":"cc45c491-cc6a-5426-ab72-d7c6d26c3614","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}