View source for 6c93


==Effects of the E310A Mutation of Cytochrome P450 4B1 (CYP4B1) on n-Octane binding and Heme Ruffling==
<StructureSection load='6c93' size='340' side='right'caption='[[6c93]], [[Resolution|resolution]] 2.67&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6c93]] 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=6C93 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6C93 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]] 2.674&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=OCT:N-OCTANE'>OCT</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=6c93 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6c93 OCA], [https://pdbe.org/6c93 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6c93 RCSB], [https://www.ebi.ac.uk/pdbsum/6c93 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6c93 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CP4B1_RABIT CP4B1_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.
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== Publication Abstract from PubMed ==
Cytochrome P450 4B1 (4B1) functions in both xenobiotic and endobiotic metabolism. An ester linkage between Glu-310 in 4B1 and the 5-methyl group of heme facilitates preferential hydroxylation of terminal (omega) methyl groups of hydrocarbons (HCs) and fatty acids compared with omega-1 sites bearing weaker C-H bonds. This preference is retained albeit diminished 4-fold for the E310A mutant, but the reason for this is unclear. Here, a crystal structure of the E310A-octane complex disclosed that noncovalent interactions maintain heme deformation in the absence of the ester linkage. Consistent with the lower symmetry of the heme, resonance Raman (RR) spectroscopy revealed large enhancements of RR peaks for high-spin HC complexes of 4B1 and the E310A mutant relative to P450 3A4. While these enhancements were diminished in RR spectra of a low-spin 4B1-N-hydroxy-N'-(4-butyl-2-methylphenyl)formamidine complex, a crystal structure indicated that this inhibitor does not alter heme ruffling. RR spectra of Fe2+-CO HC complexes revealed larger effects of HC length in E310A than in 4B1, suggesting that reduced rigidity likely underlies increased E310A-catalyzed (omega-1)-hydroxylation. Diminished effects of the HC on the position of the Fe-CO stretching mode in 4B1 suggested that the ester linkage limits substrate access to the CO. Heme ruffling likely facilitates autocatalytic ester formation by reducing inhibitory coordination of Glu-310 with the heme iron. This also positions the 5-methyl for a reaction with the proposed glutamyl radical intermediate and potentially enhances oxo-ferryl intermediate reactivity for generation of the glutamyl radical to initiate ester bond formation and omega-hydroxylation.

Non-covalent interactions dominate dynamic heme distortion in cytochrome P450 4B1.,Jennings GK, Hsu MH, Shock LS, Johnson EF, Hackett JC J Biol Chem. 2018 Jun 1. pii: RA118.004044. doi: 10.1074/jbc.RA118.004044. PMID:29858244<ref>PMID:29858244</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 6c93" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome P450 3D structures|Cytochrome P450 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Oryctolagus cuniculus]]
[[Category: Hsu M-H]]
[[Category: Johnson EF]]