{"id":"2662abfd-1121-5978-9ad3-e78df2dc7ca2","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-kat2-plp","predicate":"uses_cofactor","statement":"Human KAT-II/AADAT is a PLP-dependent homodimer; the structure shows a PLP–Lys263 aldimine at its catalytic site.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"fa150df2-b2e6-5d41-a905-6cb89933fb20","mechanism_event_label":"Vitamin B6 participates in a branch enzyme, not only the serotonin route.","subject":{"id":"b0d4ed40-858b-50e8-acbb-669452624d93","slug":"aadat","display_name":"AADAT / KAT II","entity_type_key":"protein"},"object":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"fa150df2-b2e6-5d41-a905-6cb89933fb20","stable_key":"584c58f5-ab9f-53f3-97a9-55783db943b0:tryptophan-kat2-plp-event","event_type":"observed_relationship","label":"Vitamin B6 participates in a branch enzyme, not only the serotonin route.","description":"Human KAT-II/AADAT is a PLP-dependent homodimer; the structure shows a PLP–Lys263 aldimine at its catalytic site.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"b0d4ed40-858b-50e8-acbb-669452624d93","slug":"aadat","display_name":"AADAT / KAT II","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"769339cb-213b-559e-acc0-07ed00368b94","slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"ce72cbd6-7077-5f23-a859-a8000a3f8194","slug":"kynurenine","display_name":"L-Kynurenine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"6a123629-5a43-57ef-bba0-c429005ab5b3","slug":"kynurenic-acid","display_name":"Kynurenic acid","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":"Human KAT-II crystal structure at 1.83 angstrom resolution.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Cofactor dependence alone does not define clinical B6 requirements or benefit from excess B6.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Tryptophan collection; molecular form, preparation, species, exposure and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-tryptophan","display_name":"L-Tryptophan","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"Vitamin B6 participates in a branch enzyme, not only the serotonin route.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Structure of the PLP-Form of the Human Kynurenine Aminotransferase II in a Novel Spacegroup at 1.83 Å Resolution. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27023527/ · DOI 10.3390/ijms17040446","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"68cde36f-8ea4-5c22-9a88-35fb28ea0b9e","evidence_kind":"source_excerpt","locator":"Lines 202-208","start_line":202,"end_line":208,"excerpt":"## tryptophan-kat2-plp\nVitamin B6 participates in a branch enzyme, not only the serotonin route.\nHuman KAT-II/AADAT is a PLP-dependent homodimer; the structure shows a PLP–Lys263 aldimine at its catalytic site.\nModel: Human KAT-II crystal structure at 1.83 angstrom resolution.\nLimitations: Cofactor dependence alone does not define clinical B6 requirements or benefit from excess B6.\nEvidence access: Primary abstract\nStructure of the PLP-Form of the Human Kynurenine Aminotransferase II in a Novel Spacegroup at 1.83 Å Resolution. · 2016 · https://pubmed.ncbi.nlm.nih.gov/27023527/ · DOI 10.3390/ijms17040446","model_system":"Human KAT-II crystal structure at 1.83 angstrom resolution.","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":"73f9d3e7-fdc9-5418-8f3c-f4ef145f6efa","stable_key":"import-584c58f5-ab9f-53f3-97a9-55783db943b0","title":"Tryptophan: transport, protein synthesis, neuroactive metabolites, NAD and microbial pathways (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":"7dfd20063b91900cb5c6ad675e3e675b7e25ef0fb8304eabac6f263cc5518284","revision_id":"bfafd789-fdf5-521f-bd28-c662e01ec1ea","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}