View source for 4mgj


==Crystal structure of cytochrome P450 2B4 F429H in complex with 4-CPI==
<StructureSection load='4mgj' size='340' side='right'caption='[[4mgj]], [[Resolution|resolution]] 2.41&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4mgj]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Oryctolagus_cuniculus Oryctolagus cuniculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4MGJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4MGJ FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.41&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CPZ:4-(4-CHLOROPHENYL)IMIDAZOLE'>CPZ</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4mgj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4mgj OCA], [https://pdbe.org/4mgj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4mgj RCSB], [https://www.ebi.ac.uk/pdbsum/4mgj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4mgj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CP2B4_RABIT CP2B4_RABIT] Cytochromes P450 are a group of heme-thiolate monooxygenases. In liver microsomes, this enzyme is involved in an NADPH-dependent electron transport pathway. It oxidizes a variety of structurally unrelated compounds, including steroids, fatty acids, and xenobiotics. In the epoxidation of arachidonic acid it has a unique preference for the 5,6-olefin.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The structural basis of the regulation of microsomal cytochrome P450 (P450) activity was investigated by mutating the highly conserved heme binding motif residue, Phe429, on the proximal side of cytochrome P450 2B4 to a histidine. Spectroscopic, pre-steady-state and steady-state kinetic, thermodynamic, theoretical, and structural studies of the mutant demonstrate that formation of an H-bond between His429 and the unbonded electron pair of the Cys436 axial thiolate significantly alters the properties of the enzyme. The mutant lost &gt;90% of its activity; its redox potential was increased by 87 mV, and the half-life of the oxyferrous mutant was increased approximately 37-fold. Single-crystal electronic absorption and resonance Raman spectroscopy demonstrated that the mutant was reduced by a small dose of X-ray photons. The structure revealed that the deltaN atom of His429 forms an H-bond with the axial Cys436 thiolate whereas the epsilonN atom forms an H-bond with the solvent and the side chain of Gln357. The amide of Gly438 forms the only other H-bond to the tetrahedral thiolate. Theoretical quantification of the histidine-thiolate interaction demonstrates a significant electron withdrawing effect on the heme iron. Comparisons of structures of class I-IV P450s demonstrate that either a phenylalanine or tryptophan is often found at the location corresponding to Phe429. Depending on the structure of the distal pocket heme, the residue at this location may or may not regulate the thermodynamic properties of the P450. Regardless, this residue appears to protect the thiolate from solvent, oxidation, protonations, and other deleterious reactions.

Structural and Functional Characterization of a Cytochrome P450 2B4 F429H Mutant with an Axial Thiolate-Histidine Hydrogen Bond.,Yang Y, Zhang H, Usharani D, Bu W, Im S, Tarasev M, Rwere F, Pearl NM, Meagher J, Sun C, Stuckey J, Shaik S, Waskell L Biochemistry. 2014 Jul 31. PMID:25029089<ref>PMID:25029089</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4mgj" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome P450 3D structures|Cytochrome P450 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Oryctolagus cuniculus]]
[[Category: Bu W]]
[[Category: Im S]]
[[Category: Meagher J]]
[[Category: Rwere F]]
[[Category: Shaik S]]
[[Category: Stuckey J]]
[[Category: Sun C]]
[[Category: Tarasev M]]
[[Category: Usharani D]]
[[Category: Waskell L]]
[[Category: Yang Y]]
[[Category: Zhang H]]