{"id":"6ba94f15-35e8-5608-9687-90e3c7567778","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-cth-plp","predicate":"cofactor-for","statement":"PLP binds human CTH at Lys212 in an active site assembled from adjacent subunits.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"9e35eb12-fcb9-5bfe-bed4-b69e71f52f55","mechanism_event_label":"CTH needs an assembled B6-binding catalytic site.","subject":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"object":{"id":"4014ee3a-0e44-5379-b541-174aa75bcf90","slug":"cth","display_name":"Human cystathionine gamma-lyase / CTH","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"9e35eb12-fcb9-5bfe-bed4-b69e71f52f55","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-cth-plp-event","event_type":"biochemical_relationship","label":"CTH needs an assembled B6-binding catalytic site.","description":"PLP binds human CTH at Lys212 in an active site assembled from adjacent subunits.","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":"4014ee3a-0e44-5379-b541-174aa75bcf90","slug":"cth","display_name":"Human cystathionine gamma-lyase / CTH","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Second PLP-dependent step of sulfur amino-acid transsulfuration.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Apo, PLP and PLP-PAG structural comparisons","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Purified human CTH apo/holo crystal structures and assays","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":"CTH needs an assembled B6-binding catalytic site.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b6-cth-structure-2009] Structural Basis for the Inhibition Mechanism of Human Cystathionine gamma-Lyase, an Enzyme Responsible for the Production of H2S (2009). https://doi.org/10.1074/jbc.M805459200 DOI: 10.1074/jbc.M805459200","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":"a2a8c9e3-aebc-5cd3-8488-a094bd0881f1","evidence_kind":"source_excerpt","locator":"Lines 541-552","start_line":541,"end_line":552,"excerpt":"### b6-met-cth-plp\nPLP binds human CTH at Lys212 in an active site assembled from adjacent subunits.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: CTH needs an assembled B6-binding catalytic site.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Purified human CTH apo/holo crystal structures and assays\nlimitations: Purified-enzyme evidence does not define dietary requirements or cellular PLP thresholds.\ncross_nutrient: Second PLP-dependent step of sulfur amino-acid transsulfuration.\nevidence_location: Apo, PLP and PLP-PAG structural comparisons\n[b6-cth-structure-2009] Structural Basis for the Inhibition Mechanism of Human Cystathionine gamma-Lyase, an Enzyme Responsible for the Production of H2S (2009). https://doi.org/10.1074/jbc.M805459200 DOI: 10.1074/jbc.M805459200","model_system":"Purified human CTH apo/holo crystal structures and assays","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b6-cth-structure-2009] Structural Basis for the Inhibition Mechanism of Human Cystathionine gamma-Lyase, an Enzyme Responsible for the Production of H2S (2009). https://doi.org/10.1074/jbc.M805459200 DOI: 10.1074/jbc.M805459200","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}