{"id":"7ff8db5c-466b-52a8-826d-d1053865ca80","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-bcat2-pmp","predicate":"forms-catalytic-intermediate-with","statement":"Human BCAT2 structures capture the isoleucine ketimine and PMP forms of its amino-transfer cycle.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"1cd1835f-45d0-5e04-a14b-c699523b3b38","mechanism_event_label":"The cofactor cycles between PLP and PMP as it carries an amino group.","subject":{"id":"078444ed-0927-573a-b54d-5fdabb5d04ae","slug":"bcat2","display_name":"Human mitochondrial branched-chain aminotransferase / BCAT2","entity_type_key":"protein"},"object":{"id":"c8dec85c-c85d-5a55-ba85-ad3c1b3e332b","slug":"pyridoxamine-phosphate","display_name":"Pyridoxamine 5-prime-phosphate","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"1cd1835f-45d0-5e04-a14b-c699523b3b38","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-bcat2-pmp-event","event_type":"biochemical_relationship","label":"The cofactor cycles between PLP and PMP as it carries an amino group.","description":"Human BCAT2 structures capture the isoleucine ketimine and PMP forms of its amino-transfer cycle.","status":"provisional","compartment":{"slug":"mitochondrial-matrix","display_name":"Mitochondrial matrix"},"participants":[{"entity":{"id":"078444ed-0927-573a-b54d-5fdabb5d04ae","slug":"bcat2","display_name":"Human mitochondrial branched-chain aminotransferase / BCAT2","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"c85b327e-f132-5d9a-8e4b-c2976fcc0373","slug":"isoleucine","display_name":"L-Isoleucine","entity_type_key":"small_molecule"},"role":"amino donor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"initial cofactor form","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"c8dec85c-c85d-5a55-ba85-ad3c1b3e332b","slug":"pyridoxamine-phosphate","display_name":"Pyridoxamine 5-prime-phosphate","entity_type_key":"small_molecule"},"role":"aminated cofactor form","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Human BCAT2 reaction-intermediate crystallography","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Purified-enzyme evidence does not define dietary requirements or cellular PLP thresholds.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-b6","display_name":"Vitamin B6","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"The cofactor cycles between PLP and PMP as it carries an amino group.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b6-bcat2-2002] Crystal structures of human mitochondrial branched chain aminotransferase reaction intermediates: ketimine and pyridoxamine phosphate forms (2002). https://pubmed.ncbi.nlm.nih.gov/12269802/ DOI: 10.1021/bi020221c","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified recombinant protein; no intact tissue","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"15946525-afee-5d87-a6e8-74065fa34836","evidence_kind":"source_excerpt","locator":"Lines 706-715","start_line":706,"end_line":715,"excerpt":"### b6-met-bcat2-pmp\nHuman BCAT2 structures capture the isoleucine ketimine and PMP forms of its amino-transfer cycle.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The cofactor cycles between PLP and PMP as it carries an amino group.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Human BCAT2 reaction-intermediate crystallography\nlimitations: Purified-enzyme evidence does not define dietary requirements or cellular PLP thresholds.\n[b6-bcat2-2002] Crystal structures of human mitochondrial branched chain aminotransferase reaction intermediates: ketimine and pyridoxamine phosphate forms (2002). https://pubmed.ncbi.nlm.nih.gov/12269802/ DOI: 10.1021/bi020221c","model_system":"Human BCAT2 reaction-intermediate crystallography","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b6-bcat2-2002] Crystal structures of human mitochondrial branched chain aminotransferase reaction intermediates: ketimine and pyridoxamine phosphate forms (2002). https://pubmed.ncbi.nlm.nih.gov/12269802/ DOI: 10.1021/bi020221c","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"251773bb-16f5-5903-b135-db4a61d9dec4","stable_key":"import-1310afbd-6010-586e-805d-551d846da421","title":"Vitamin B6: mechanisms, deficiency and nutrient interactions (2026-09-17)","document_type":"imported_text","citation_label":"AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text.","file_path":"","sha256":"ef0019b344b2219220f801a84d0d138ff6880c1be1a59540d9034bfa4334f61e","revision_id":"cac3555f-48af-5c52-a84e-add4482c87fb","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}