3A4Z:
reference: Structural evidence for enhancement of sequential vitamin D3 hydroxylation activities by directed evolution of cytochrome P450 vitamin D3 hydroxylase., Yasutake Y, Fujii Y, Nishioka T, Cheon WK, Arisawa A, Tamura T, J Biol Chem. 2010 Oct 8;285(41):31193-201. Epub 2010 Jul 27. PMID: 20667833

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