Introduction
Rickets is a disease caused by a vitamin D deficiency. Vitamin D can be obtained from ultra violet radiation and from various food sources. Cytochrome P450 enzymes are involved in the first step to regulate and process vitamin D in the human body.
Overall Structure
- Asymmetric dimer
- Consists of α-helices, β-sheets (mostly on one side of the molecule) with a heme buried inside the protein
- Two molecules of 2-hydroxypropyl-β-cyclodextrin are found near the dimer interface
Binding Interactions
The binding of Vitamin D3 occurs in a channel between the G and I helices and B' helix and B-C loop. In the you can see the residues that interact to bind Vitamin D3 and the channel between. Most of these residues are hydrophobic and thus have non polar interactions. Binding of the substrate causes the access channel to close. The B' helix has a flexible C terminus and can adopt a helix or loop conformation, which has van der waal interactions with the F-G loop. The B' helix unwinds outward to allow entrance of the substrate into the active site channel. CYP2R1 has an extended binding site where the access channel is part of the active site.
-catalyzes initial step for converting vitamin D into 25-hydroxyvitamin D
-mutation causes rickets-25-hydroxylase deficiency
Additional Features
This molecule has a heme which is bound to iron, which, combined with its structural conformation, allows for hydroxylation with the attached substrate. This molecule carries out important functions and is not species or sex specific.
Quiz Question 1
(merely an example of what this section might look like)
rom can you identify the green, red, and blue parts of the molecule?
See Also
Credits
Introduction - Sami Kriksceonaitis
Overall Structure - Kati Johnson
Drug Binding Site - Isabel Hand
Additional Features - Elizabeth Humble
Quiz Question 1 - Matthew Tiller1
References
- ↑ Strushkevich N, Usanov SA, Plotnikov AN, Jones G, Park HW. Structural analysis of CYP2R1 in complex with vitamin D3. J Mol Biol. 2008 Jun 27;380(1):95-106. Epub 2008 Apr 8. PMID:18511070 doi:10.1016/j.jmb.2008.03.065
