3c6g
From Proteopedia
Crystal structure of CYP2R1 in complex with vitamin D3
Structural highlights
DiseaseCP2R1_HUMAN Defects in CYP2R1 are the cause of rickets vitamin D-dependent type 1B (VDDR1B) [MIM:600081; also known as pseudovitamin D(3) deficiency rickets due to 25-hydroxylase deficiency. A disorder caused by a selective deficiency of the active form of vitamin D (1,25-dihydroxyvitamin D3) and resulting in defective bone mineralization and clinical features of rickets. The patients sera have low calcium concentrations, low phosphate concentrations, elevated alkaline phosphatase activityand low levels of 25-hydroxyvitamin D.[1] FunctionCP2R1_HUMAN Has a D-25-hydroxylase activity on both forms of vitamin D, vitamin D(2) and D(3).[2] [3] [4] Evolutionary ConservationCheck, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe activation of vitamin D to its hormonal form is mediated by cytochrome P450 enzymes. CYP2R1 catalyzes the initial step converting vitamin D into 25-hydroxyvitamin D. A CYP2R1 gene mutation causes an inherited form of rickets due to 25-hydroxylase deficiency. To understand the narrow substrate specificity of CYP2R1 we obtained the hemeprotein in a highly purified state, confirmed the enzyme as a vitamin D 25-hydroxylase, and solved the crystal structure of CYP2R1 in complex with vitamin D3. The CYP2R1 structure adopts a closed conformation with the substrate access channel being covered by the ordered B'-helix and slightly opened to the surface, which defines the substrate entrance point. The active site is lined by conserved, mostly hydrophobic residues. Vitamin D3 is bound in an elongated conformation with the aliphatic side-chain pointing toward the heme. The structure reveals the secosteroid binding mode in an extended active site and allows rationalization of the molecular basis of the inherited rickets associated with CYP2R1. Structural analysis of CYP2R1 in complex with vitamin D3.,Strushkevich N, Usanov SA, Plotnikov AN, Jones G, Park HW J Mol Biol. 2008 Jun 27;380(1):95-106. Epub 2008 Apr 8. PMID:18511070[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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