{"id":"bc06906d-b3df-51e6-b5b6-ff0d6c3532f7","stable_key":"1deb434a-3547-51a0-a038-87b1ce79ec38:vd-act-por-fmn","predicate":"binds_cofactor","statement":"Crystallography and extracted-flavin analysis identified FMN bound to recombinant human POR.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"neutral","is_public":true,"mechanism_event_id":"2c6c82ac-a9d8-50e2-a293-9b606deaad69","mechanism_event_label":"POR carries a FMN cofactor derived from vitamin B2.","subject":{"id":"9a730557-ae90-5bf9-a716-c13a6ceef49b","slug":"por","display_name":"NADPH-cytochrome P450 oxidoreductase / POR","entity_type_key":"protein"},"object":{"id":"d3eacf85-1a35-546d-bd30-161474dd9691","slug":"fmn","display_name":"Flavin mononucleotide","entity_type_key":"small_molecule"},"evidence_count":1,"mechanism_event":{"id":"2c6c82ac-a9d8-50e2-a293-9b606deaad69","stable_key":"1deb434a-3547-51a0-a038-87b1ce79ec38:vd-act-por-fmn-event","event_type":"biochemical_relationship","label":"POR carries a FMN cofactor derived from vitamin B2.","description":"Crystallography and extracted-flavin analysis identified FMN bound to recombinant human POR.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"9a730557-ae90-5bf9-a716-c13a6ceef49b","slug":"por","display_name":"NADPH-cytochrome P450 oxidoreductase / POR","entity_type_key":"protein"},"role":"redox_protein","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"d3eacf85-1a35-546d-bd30-161474dd9691","slug":"fmn","display_name":"Flavin mononucleotide","entity_type_key":"small_molecule"},"role":"bound_cofactor","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"86eb1eee-a8d1-539c-8c17-0911f69b6f1b","slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"},"role":"cofactor_precursor","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"true","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Primary Results, wild-type structure and cofactor-binding sites; Methods flavin extraction/HPLC.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Human POR structure and flavin-content analysis","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Recombinant N-terminally truncated human POR; X-ray structure and HPLC flavin assays.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"The structural study did not measure vitamin D outcomes after riboflavin dosing; linkage to CYP2R1 comes from the separate direct reconstitution record.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient","value_text":"Vitamin D2 and D3","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-d","display_name":"Vitamin D2 and D3","entity_type_key":"chemical_species"}},{"dimension":"nutrient_topic","value_text":"Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"vitamin-d","display_name":"Vitamin D2 and D3","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Homo sapiens protein","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"POR carries a FMN cofactor derived from vitamin B2.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[xia2011] Structural basis for human NADPH-cytochrome P450 oxidoreductase deficiency. (2011). https://pubmed.ncbi.nlm.nih.gov/21808038/ DOI: 10.1073/pnas.1106632108","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"POR cofactor-binding domain","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"a1d52001-14d5-5ae7-b963-038828972d10","evidence_kind":"source_excerpt","locator":"Lines 422-435","start_line":422,"end_line":435,"excerpt":"### vd-act-por-fmn\nCrystallography and extracted-flavin analysis identified FMN bound to recombinant human POR.\nCondition category: normal\nnutrient_topic: Vitamin D2 and D3 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: POR carries a FMN cofactor derived from vitamin B2.\norganism: Homo sapiens protein\ntissue_or_cell_type: POR cofactor-binding domain\nexperimental_model: Human POR structure and flavin-content analysis\nlimitations: The structural study did not measure vitamin D outcomes after riboflavin dosing; linkage to CYP2R1 comes from the separate direct reconstitution record.\nexposure: Recombinant N-terminally truncated human POR; X-ray structure and HPLC flavin assays.\ncross_nutrient: true\nevidence_location: Primary Results, wild-type structure and cofactor-binding sites; Methods flavin extraction/HPLC.\nnutrient: Vitamin D2 and D3\n[xia2011] Structural basis for human NADPH-cytochrome P450 oxidoreductase deficiency. (2011). https://pubmed.ncbi.nlm.nih.gov/21808038/ DOI: 10.1073/pnas.1106632108","model_system":"Human POR structure and flavin-content analysis","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [xia2011] Structural basis for human NADPH-cytochrome P450 oxidoreductase deficiency. (2011). https://pubmed.ncbi.nlm.nih.gov/21808038/ DOI: 10.1073/pnas.1106632108","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"c95c763c-5b31-5b3f-a2f8-2dfe5ef0d3ca","stable_key":"import-1deb434a-3547-51a0-a038-87b1ce79ec38","title":"Vitamin D2 and D3: 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. 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