{"id":"fbec14e7-d141-5f7b-8686-f4961c9f6112","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-cbs-plp","predicate":"cofactor-for","statement":"The human CBS catalytic core binds PLP through its active-site lysine; this site is separate from the heme-binding region.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"034494d7-5fe2-57db-bd68-4a4566cec1e1","mechanism_event_label":"CBS uses active vitamin B6 in its catalytic site.","subject":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"object":{"id":"4688e32c-d7b6-5fca-9eb2-23307c29ae07","slug":"cbs","display_name":"Human cystathionine beta-synthase / CBS","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"034494d7-5fe2-57db-bd68-4a4566cec1e1","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-cbs-plp-event","event_type":"biochemical_relationship","label":"CBS uses active vitamin B6 in its catalytic site.","description":"The human CBS catalytic core binds PLP through its active-site lysine; this site is separate from the heme-binding region.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"role":"cofactor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"4688e32c-d7b6-5fca-9eb2-23307c29ae07","slug":"cbs","display_name":"Human cystathionine beta-synthase / CBS","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Vitamin B6 and sulfur amino-acid metabolism.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Recombinant truncated human CBS crystallography","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The crystallized human construct lacks the C-terminal regulatory region.","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":"CBS uses active vitamin B6 in its catalytic site.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b6-cbs-2001] Structure of human cystathionine beta-synthase: a unique pyridoxal 5'-phosphate-dependent heme protein. (2001). https://pmc.ncbi.nlm.nih.gov/articles/PMC149156/ DOI: 10.1093/emboj/20.15.3910","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":"3227c545-ef5b-586a-ac98-d4009264677c","evidence_kind":"source_excerpt","locator":"Lines 505-515","start_line":505,"end_line":515,"excerpt":"### b6-met-cbs-plp\nThe human CBS catalytic core binds PLP through its active-site lysine; this site is separate from the heme-binding region.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: CBS uses active vitamin B6 in its catalytic site.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Recombinant truncated human CBS crystallography\nlimitations: The crystallized human construct lacks the C-terminal regulatory region.\ncross_nutrient: Vitamin B6 and sulfur amino-acid metabolism.\n[b6-cbs-2001] Structure of human cystathionine beta-synthase: a unique pyridoxal 5'-phosphate-dependent heme protein. (2001). https://pmc.ncbi.nlm.nih.gov/articles/PMC149156/ DOI: 10.1093/emboj/20.15.3910","model_system":"Recombinant truncated human CBS crystallography","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b6-cbs-2001] Structure of human cystathionine beta-synthase: a unique pyridoxal 5'-phosphate-dependent heme protein. (2001). https://pmc.ncbi.nlm.nih.gov/articles/PMC149156/ DOI: 10.1093/emboj/20.15.3910","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}