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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.fulltext.txt\", \"locator\": \"Exact primary full-text span; zero-based, end-exclusive Unicode character offsets\", \"file_sha256\": \"bbd73607ba2570aa383c81c189b29dd19f1cbd7bf7acdd8343ecf3ee7dc5faf8\", \"start_char\": 45325, \"end_char\": 45633, \"text_sha256\": \"6ae5b000cbc7fa6b682d2b2a915102061ea7bd2e3a3941a1bce8ed98ce0ee016\"}\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. 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