1p0x: Difference between revisions
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== | ==F393Y mutant heme domain of flavocytochrome P450 BM3== | ||
In flavocytochrome P450 BM3, there is a conserved phenylalanine residue at | <StructureSection load='1p0x' size='340' side='right'caption='[[1p0x]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1p0x]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Priestia_megaterium Priestia megaterium]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1P0X OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1P0X 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]] 2Å</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></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=1p0x FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1p0x OCA], [https://pdbe.org/1p0x PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1p0x RCSB], [https://www.ebi.ac.uk/pdbsum/1p0x PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1p0x ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/CPXB_PRIM2 CPXB_PRIM2] Functions as a fatty acid monooxygenase (PubMed:3106359, PubMed:1727637, PubMed:16566047, PubMed:7578081, PubMed:11695892, PubMed:14653735, PubMed:16403573, PubMed:18004886, PubMed:17077084, PubMed:17868686, PubMed:18298086, PubMed:18619466, PubMed:18721129, PubMed:19492389, PubMed:20180779, PubMed:21110374, PubMed:21875028). Catalyzes hydroxylation of fatty acids at omega-1, omega-2 and omega-3 positions (PubMed:1727637, PubMed:21875028). Shows activity toward medium and long-chain fatty acids, with optimum chain lengths of 12, 14 and 16 carbons (lauric, myristic, and palmitic acids). Able to metabolize some of these primary metabolites to secondary and tertiary products (PubMed:1727637). Marginal activity towards short chain lengths of 8-10 carbons (PubMed:1727637, PubMed:18619466). Hydroxylates highly branched fatty acids, which play an essential role in membrane fluidity regulation (PubMed:16566047). Also displays a NADPH-dependent reductase activity in the C-terminal domain, which allows electron transfer from NADPH to the heme iron of the cytochrome P450 N-terminal domain (PubMed:3106359, PubMed:1727637, PubMed:16566047, PubMed:7578081, PubMed:11695892, PubMed:14653735, PubMed:16403573, PubMed:18004886, PubMed:17077084, PubMed:17868686, PubMed:18298086, PubMed:18619466, PubMed:18721129, PubMed:19492389, PubMed:20180779, PubMed:21110374, PubMed:21875028). Involved in inactivation of quorum sensing signals of other competing bacteria by oxidazing efficiently acyl homoserine lactones (AHLs), molecules involved in quorum sensing signaling pathways, and their lactonolysis products acyl homoserines (AHs) (PubMed:18020460).<ref>PMID:11695892</ref> <ref>PMID:14653735</ref> <ref>PMID:16403573</ref> <ref>PMID:16566047</ref> <ref>PMID:17077084</ref> <ref>PMID:1727637</ref> <ref>PMID:17868686</ref> <ref>PMID:18004886</ref> <ref>PMID:18020460</ref> <ref>PMID:18298086</ref> <ref>PMID:18619466</ref> <ref>PMID:18721129</ref> <ref>PMID:19492389</ref> <ref>PMID:20180779</ref> <ref>PMID:21110374</ref> <ref>PMID:21875028</ref> <ref>PMID:3106359</ref> <ref>PMID:7578081</ref> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/p0/1p0x_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1p0x ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
In flavocytochrome P450 BM3, there is a conserved phenylalanine residue at position 393 (Phe393), close to Cys400, the thiolate ligand to the heme. Substitution of Phe393 by Ala, His, Tyr, and Trp has allowed us to modulate the reduction potential of the heme, while retaining the structural integrity of the enzyme's active site. Substrate binding triggers electron transfer in P450 BM3 by inducing a shift from a low- to high-spin ferric heme and a 140 mV increase in the heme reduction potential. Kinetic analysis of the mutants indicated that the spin-state shift alone accelerates the rate of heme reduction (the rate determining step for overall catalysis) by 200-fold and that the concomitant shift in reduction potential is only responsible for a modest 2-fold rate enhancement. The second step in the P450 catalytic cycle involves binding of dioxygen to the ferrous heme. The stabilities of the oxy-ferrous complexes in the mutant enzymes were also analyzed using stopped-flow kinetics. These were found to be surprisingly stable, decaying to superoxide and ferric heme at rates of 0.01-0.5 s(-)(1). The stability of the oxy-ferrous complexes was greater for mutants with higher reduction potentials, which had lower catalytic turnover rates but faster heme reduction rates. The catalytic rate-determining step of these enzymes can no longer be the initial heme reduction event but is likely to be either reduction of the stabilized oxy-ferrous complex, i.e., the second flavin to heme electron transfer or a subsequent protonation event. Modulating the reduction potential of P450 BM3 appears to tune the two steps in opposite directions; the potential of the wild-type enzyme appears to be optimized to maximize the overall rate of turnover. The dependence of the visible absorption spectrum of the oxy-ferrous complex on the heme reduction potential is also discussed. | |||
Oxygen activation and electron transfer in flavocytochrome P450 BM3.,Ost TW, Clark J, Mowat CG, Miles CS, Walkinshaw MD, Reid GA, Chapman SK, Daff S J Am Chem Soc. 2003 Dec 10;125(49):15010-20. PMID:14653735<ref>PMID:14653735</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 1p0x" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cytochrome P450 3D structures|Cytochrome P450 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Priestia megaterium]] | |||
[[Category: Chapman SK]] | |||
[[Category: Clark J]] | |||
[[Category: Daff S]] | |||
[[Category: Miles CS]] | |||
[[Category: Mowat CG]] | |||
[[Category: Ost TWB]] | |||
[[Category: Reid GA]] | |||
[[Category: Walkinshaw MD]] | |||
