{"id":"5396947e-2be7-51cf-9207-d2a0984b554f","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-ubiad1-magnesium-site","predicate":"has_inferred_binding_region_for","statement":"Mutational analysis assigned conserved domain IV to magnesium/isoprenyl-side-chain interactions.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"380b0d0e-31df-5a7b-8b02-286e030e3c58","mechanism_event_label":"Magnesium-related enzyme chemistry is recorded separately from a claim that oral magnesium improves K2 status.","subject":{"id":"190c8a9f-60f4-5341-898e-187a0c697624","slug":"ubiad1","display_name":"Human UBIAD1 prenyltransferase","entity_type_key":"protein"},"object":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"evidence_count":1,"mechanism_event":{"id":"380b0d0e-31df-5a7b-8b02-286e030e3c58","stable_key":"4fef8d72-f107-5eb5-b2fb-483ca85465e0:k2-ubiad1-magnesium-site-event","event_type":"biochemical_relationship","label":"Magnesium-related enzyme chemistry is recorded separately from a claim that oral magnesium improves K2 status.","description":"Mutational analysis assigned conserved domain IV to magnesium/isoprenyl-side-chain interactions.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"7e6d85c1-25b7-549b-9883-8e9d5d11ae3d","slug":"geranylgeranyl-diphosphate","display_name":"Geranylgeranyl diphosphate / GGPP","entity_type_key":"small_molecule"},"role":"prenyl_donor","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"190c8a9f-60f4-5341-898e-187a0c697624","slug":"ubiad1","display_name":"Human UBIAD1 prenyltransferase","entity_type_key":"protein"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"bff427ab-35f9-59c2-bb24-fd5953bbaec2","slug":"magnesium-ion","display_name":"Mg2+","entity_type_key":"ion"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"evidence_span","value_text":"{\"source_cache\": \"artifacts/k2-research/25874989.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"a3eb5f4c56ca7a3e70a32c020bba09f4fec5e91048b13a188017bf221f713a68\", \"start_char\": 0, \"end_char\": 1777, \"text_sha256\": \"a3eb5f4c56ca7a3e70a32c020bba09f4fec5e91048b13a188017bf221f713a68\"}","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Microsomal enzyme assays and mutagenesis","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"exposure","value_text":"Prenyl donors, reductant, magnesium and lipophilic statins","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"In-vitro substrate and assay context. Residual microsomal magnesium prevents concluding that synthesis is magnesium-independent; no human supplementation effect was tested.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.","comparator":null,"unit":null,"notes":"","entity":{"slug":"k2","display_name":"Vitamin K2 / menaquinone family","entity_type_key":"chemical_species"}},{"dimension":"organism","value_text":"Human UBIAD1 expressed in Sf9 insect cells","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"plain_language","value_text":"Magnesium-related enzyme chemistry is recorded separately from a claim that oral magnesium improves K2 status.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"[k2-p25874989] Functional characterization of the vitamin K2 biosynthetic enzyme UBIAD1. (2015). https://pubmed.ncbi.nlm.nih.gov/25874989/ DOI: 10.1371/journal.pone.0125737","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Microsomal prenylation","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"719d1d9e-d99e-50ec-8e8b-8787d9a776fd","evidence_kind":"source_excerpt","locator":"Lines 214-225","start_line":214,"end_line":225,"excerpt":"### k2-ubiad1-magnesium-site\nMutational analysis assigned conserved domain IV to magnesium/isoprenyl-side-chain interactions.\nCondition category: normal\nnutrient_topic: Vitamin K2 research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: Magnesium-related enzyme chemistry is recorded separately from a claim that oral magnesium improves K2 status.\norganism: Human UBIAD1 expressed in Sf9 insect cells\ntissue_or_cell_type: Microsomal prenylation\nexperimental_model: Microsomal enzyme assays and mutagenesis\nlimitations: In-vitro substrate and assay context. Residual microsomal magnesium prevents concluding that synthesis is magnesium-independent; no human supplementation effect was tested.\nexposure: Prenyl donors, reductant, magnesium and lipophilic statins\nevidence_span: {\"source_cache\": \"artifacts/k2-research/25874989.abstract.txt\", \"locator\": \"Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"a3eb5f4c56ca7a3e70a32c020bba09f4fec5e91048b13a188017bf221f713a68\", \"start_char\": 0, \"end_char\": 1777, \"text_sha256\": \"a3eb5f4c56ca7a3e70a32c020bba09f4fec5e91048b13a188017bf221f713a68\"}\n[k2-p25874989] Functional characterization of the vitamin K2 biosynthetic enzyme UBIAD1. (2015). https://pubmed.ncbi.nlm.nih.gov/25874989/ DOI: 10.1371/journal.pone.0125737","model_system":"Microsomal enzyme assays and mutagenesis","directness":"author_interpretation","verification_status":"source_derived_draft","notes":"Exact curation-document quotation, not publisher quotation. Study references: [k2-p25874989] Functional characterization of the vitamin K2 biosynthetic enzyme UBIAD1. (2015). https://pubmed.ncbi.nlm.nih.gov/25874989/ DOI: 10.1371/journal.pone.0125737","relationship":"supports","weight":1.0,"link_notes":"","source":{"id":"dfeae572-af3d-5042-a10e-e67596f9ab28","stable_key":"import-4fef8d72-f107-5eb5-b2fb-483ca85465e0","title":"Vitamin K2: menaquinone forms, carboxylation, recycling 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":"dc31aff21110d09b025c177e03b4c5ca8349d52bf5f962285fdbfcf660c0e4f6","revision_id":"850887db-34f6-55aa-9d3e-b8fd3a4a5de3","review_status":"unverified_draft","notes":""}}],"relations":[],"conflicts":[],"corrections":[],"research":null}