{"id":"e2eb70ee-55be-554e-b6a5-72500820db6d","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-rfk-magnesium-coordination","predicate":"coordinates-at","statement":"Human RFK crystallized with MgADP and FMN showed magnesium coordination by an FMN phosphate oxygen and Asn36.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"positive","is_public":true,"mechanism_event_id":"e58aa92d-ad3d-50fa-be87-697ee4060e94","mechanism_event_label":"Magnesium participates directly in the RFK active site.","subject":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"object":{"id":"96f56b42-6b88-54d2-b35c-24a1f52fddde","slug":"rfk","display_name":"Riboflavin kinase / RFK","entity_type_key":"protein"},"evidence_count":1,"mechanism_event":{"id":"e58aa92d-ad3d-50fa-be87-697ee4060e94","stable_key":"548ab9d6-3a9b-5bed-879c-17d03813b636:transport-rfk-magnesium-coordination-event","event_type":"biochemical_relationship","label":"Magnesium participates directly in the RFK active site.","description":"Human RFK crystallized with MgADP and FMN showed magnesium coordination by an FMN phosphate oxygen and Asn36.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"catalytic-metal","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"96f56b42-6b88-54d2-b35c-24a1f52fddde","slug":"rfk","display_name":"Riboflavin kinase / RFK","entity_type_key":"protein"},"role":"enzyme","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"55da4e38-e280-584e-a524-91ae4812c592","slug":"mg-adp","display_name":"Magnesium-ADP complex","entity_type_key":"chemical_species"},"role":"bound-product","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""},{"entity":{"id":"d3eacf85-1a35-546d-bd30-161474dd9691","slug":"fmn","display_name":"Flavin mononucleotide","entity_type_key":"small_molecule"},"role":"bound-product","stoichiometry":null,"state_label":"","sequence_order":3,"notes":""}]},"contexts":[{"dimension":"cross_nutrient","value_text":"Magnesium supports the chemistry used to activate vitamin B2; no blood-magnesium threshold is established.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"evidence_location","value_text":"Abstract; metal-coordination structural analysis","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Product-bound human RFK crystallography","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Co-crystallization with MgADP and FMN.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"A metal-bound enzyme structure is not a clinical magnesium-deficiency or supplementation experiment.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Riboflavin research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"riboflavin","display_name":"Riboflavin (vitamin B2)","entity_type_key":"small_molecule"}},{"dimension":"organism","value_text":"Homo sapiens","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Magnesium participates directly in the RFK active site.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[transport-rfk-2003] Ligand binding-induced conformational changes in riboflavin kinase: structural basis for the ordered mechanism. (2003). https://pubmed.ncbi.nlm.nih.gov/14580199/ DOI: 10.1021/bi035450t","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Purified protein","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"df4b22bc-bbbf-57ff-8bcd-d5340f23b517","evidence_kind":"source_excerpt","locator":"Lines 306-318","start_line":306,"end_line":318,"excerpt":"### transport-rfk-magnesium-coordination\nHuman RFK crystallized with MgADP and FMN showed magnesium coordination by an FMN phosphate oxygen and Asn36.\nCondition category: normal\nnutrient_topic: Riboflavin research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Magnesium participates directly in the RFK active site.\norganism: Homo sapiens\ntissue_or_cell_type: Purified protein\nexperimental_model: Product-bound human RFK crystallography\nlimitations: A metal-bound enzyme structure is not a clinical magnesium-deficiency or supplementation experiment.\nexposure: Co-crystallization with MgADP and FMN.\ncross_nutrient: Magnesium supports the chemistry used to activate vitamin B2; no blood-magnesium threshold is established.\nevidence_location: Abstract; metal-coordination structural analysis\n[transport-rfk-2003] Ligand binding-induced conformational changes in riboflavin kinase: structural basis for the ordered mechanism. (2003). https://pubmed.ncbi.nlm.nih.gov/14580199/ DOI: 10.1021/bi035450t","model_system":"Product-bound human RFK crystallography","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [transport-rfk-2003] Ligand binding-induced conformational changes in riboflavin kinase: structural basis for the ordered mechanism. (2003). https://pubmed.ncbi.nlm.nih.gov/14580199/ DOI: 10.1021/bi035450t","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"4f7c9578-82bf-5e2d-b5c4-72a79fb4f6af","stable_key":"import-548ab9d6-3a9b-5bed-879c-17d03813b636","title":"Riboflavin: 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":"680cb6bc8249877f2410f551807f10d390fdd719014137d7414ba3420e29228d","revision_id":"7a61e299-908d-5372-860b-99ed190f9d7a","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}