{"id":"0905a8ae-8caf-5c37-85bf-3071f6df1071","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-shmt1-assembly","predicate":"does-not-change","statement":"Human SHMT1 remained tetrameric with and without PLP in the tested solution conditions.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"4585f23f-6ad6-570e-8e64-538c5bbbef5c","mechanism_event_label":"SHMT1 assembly responds differently from SHMT2.","subject":{"id":"6b656ff5-9532-5da4-8eea-8ca163a48649","slug":"pyridoxal-phosphate","display_name":"PLP","entity_type_key":"small_molecule"},"object":{"id":"44858287-f0d3-5131-a765-f328d36a0afa","slug":"shmt1-tetramer-assembly","display_name":"SHMT1 tetramer assembly","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"4585f23f-6ad6-570e-8e64-538c5bbbef5c","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-shmt1-assembly-event","event_type":"biochemical_relationship","label":"SHMT1 assembly responds differently from SHMT2.","description":"Human SHMT1 remained tetrameric with and without PLP in the tested solution conditions.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"67b21ade-d4c1-574a-a78f-b980d076ad9c","slug":"shmt1","display_name":"SHMT1","entity_type_key":"protein"},"role":"enzyme","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":"cofactor presence/absence","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"44858287-f0d3-5131-a765-f328d36a0afa","slug":"shmt1-tetramer-assembly","display_name":"SHMT1 tetramer assembly","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"experimental_model","value_text":"Purified human SHMT1 and SHMT2; structures and solution oligomerization","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Tetramer persistence does not mean cofactor-free SHMT1 can perform normal catalysis.","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":"SHMT1 assembly responds differently from SHMT2.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[b6-shmt-2015] How pyridoxal 5'-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state (2015). https://febs.onlinelibrary.wiley.com/doi/10.1111/febs.13211 DOI: 10.1111/febs.13211","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":"4b476eae-9b2b-592a-a6fe-e6815dcfb519","evidence_kind":"source_excerpt","locator":"Lines 637-646","start_line":637,"end_line":646,"excerpt":"### b6-met-shmt1-assembly\nHuman SHMT1 remained tetrameric with and without PLP in the tested solution conditions.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: SHMT1 assembly responds differently from SHMT2.\norganism: Homo sapiens\ntissue_or_cell_type: Purified recombinant protein; no intact tissue\nexperimental_model: Purified human SHMT1 and SHMT2; structures and solution oligomerization\nlimitations: Tetramer persistence does not mean cofactor-free SHMT1 can perform normal catalysis.\n[b6-shmt-2015] How pyridoxal 5'-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state (2015). https://febs.onlinelibrary.wiley.com/doi/10.1111/febs.13211 DOI: 10.1111/febs.13211","model_system":"Purified human SHMT1 and SHMT2; structures and solution oligomerization","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [b6-shmt-2015] How pyridoxal 5'-phosphate differentially regulates human cytosolic and mitochondrial serine hydroxymethyltransferase oligomeric state (2015). https://febs.onlinelibrary.wiley.com/doi/10.1111/febs.13211 DOI: 10.1111/febs.13211","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}