{"id":"79d0d1fb-6747-55ac-92dc-29b2e44457e2","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-shmt1-onecarbon","predicate":"catalyzes-formation-of","statement":"Human SHMT1 uses PLP to couple serine-to-glycine conversion with transfer of a one-carbon unit to tetrahydrofolate.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"399f7744-aede-514a-b2fc-6978f6c3eca4","mechanism_event_label":"The enzyme connects B6-dependent amino-acid chemistry to folate chemistry.","subject":{"id":"67b21ade-d4c1-574a-a78f-b980d076ad9c","slug":"shmt1","display_name":"SHMT1","entity_type_key":"protein"},"object":{"id":"0413b195-325e-5757-a72b-f445d65c17bc","slug":"5-10-methylenetetrahydrofolate","display_name":"5,10-Methylenetetrahydrofolate","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"399f7744-aede-514a-b2fc-6978f6c3eca4","stable_key":"1310afbd-6010-586e-805d-551d846da421:b6-met-shmt1-onecarbon-event","event_type":"biochemical_relationship","label":"The enzyme connects B6-dependent amino-acid chemistry to folate chemistry.","description":"Human SHMT1 uses PLP to couple serine-to-glycine conversion with transfer of a one-carbon unit to tetrahydrofolate.","status":"provisional","compartment":{"slug":"cytosol","display_name":"Cytosol"},"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","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"c882cd0b-9d83-5b07-bd1c-fe4d45657dcb","slug":"l-serine","display_name":"L-Serine","entity_type_key":"small_molecule"},"role":"substrate","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"2b507258-430c-51fe-9fd2-e510c2c197a9","slug":"glycine","display_name":"Glycine","entity_type_key":"small_molecule"},"role":"product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""},{"entity":{"id":"d2b23343-c688-5fc3-9f42-bfac0050552b","slug":"tetrahydrofolate","display_name":"Tetrahydrofolate","entity_type_key":"small_molecule"},"role":"one-carbon acceptor","stoichiometry":null,"state_label":"","sequence_order":4,"notes":""},{"entity":{"id":"0413b195-325e-5757-a72b-f445d65c17bc","slug":"5-10-methylenetetrahydrofolate","display_name":"5,10-Methylenetetrahydrofolate","entity_type_key":"small_molecule"},"role":"one-carbon product","stoichiometry":null,"state_label":"","sequence_order":5,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"PLP (B6) and THF (folate) cooperate in one reaction.","comparator":null,"unit":null,"notes":"","entity":null},{"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":"Reaction is reversible; assembly assays do not establish flux in every cell.","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 enzyme connects B6-dependent amino-acid chemistry to folate chemistry.","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":"39045c54-3dd4-5316-818c-282499763f62","evidence_kind":"source_excerpt","locator":"Lines 602-612","start_line":602,"end_line":612,"excerpt":"### b6-met-shmt1-onecarbon\nHuman SHMT1 uses PLP to couple serine-to-glycine conversion with transfer of a one-carbon unit to tetrahydrofolate.\nCondition category: normal\nnutrient_topic: Vitamin B6 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: The enzyme connects B6-dependent amino-acid chemistry to folate chemistry.\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: Reaction is reversible; assembly assays do not establish flux in every cell.\ncross_nutrient: PLP (B6) and THF (folate) cooperate in one reaction.\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}