View source for 6p41


==Yeast cytochrome c peroxidase (W191Y:L232E) in complex with iso-1 cytochrome c==
<StructureSection load='6p41' size='340' side='right'caption='[[6p41]], [[Resolution|resolution]] 2.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6p41]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Saccharomyces_cerevisiae_S288C Saccharomyces cerevisiae S288C]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6P41 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6P41 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]] 2.9&#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></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=6p41 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6p41 OCA], [https://pdbe.org/6p41 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6p41 RCSB], [https://www.ebi.ac.uk/pdbsum/6p41 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6p41 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CCPR_YEAST CCPR_YEAST] Destroys radicals which are normally produced within the cells and which are toxic to biological systems.
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== Publication Abstract from PubMed ==
Transient tyrosine and tryptophan radicals play key roles in the electron transfer (ET) reactions of photosystem (PS) II, ribonucleotide reductase (RNR), photolyase and many other proteins. However, Tyr and Trp are not functionally interchangeable and the factors controlling their reactivity are often unclear. Cytochrome c peroxidase (CcP) employs a Trp191(+*) radical to oxidize reduced cytochrome c (Cc). Although a Tyr191 replacement also forms a stable radical, it does not support rapid ET from Cc. Here we probe the redox properties of CcP Y191 by non-natural amino acid substitution, altering the ET driving force, and manipulating the protic environment of Y191. Higher potential fluorotyrosine residues increase ET rates marginally, but only addition of a hydrogen bond donor to Tyr191(*) (via Leu232His or Glu) rescues activity by increasing the ET rate by nearly 30-fold. ESR and ESEEM spectroscopies, crystallography, and pH-dependent ET kinetics provide strong evidence for hydrogen bond formation to Y191(*) by His232/Glu232. Rate measurements and rapid freeze quench ESR spectroscopy further reveal differences in radical propagation and Cc oxidation that support an increased Y191(*) reduction potential of approximately 200 mV in the presence of E232. Hence, Y191 inactivity results from a reduction potential drop owing to Y191(*+) deprotonation. Incorporation of a well-positioned base to accept and donate back a hydrogen bond upshifts the Tyr(*) potential into a range where it can effectively oxidize Cc. These findings have implications for the YZ/YD radicals of PS II, hole-hopping in RNR and cryptochrome, and engineering proteins for long-range ET reactions.

Tuning radical relay residues by proton management rescues protein electron hopping.,Yee EF, Dzikovski B, Crane BR J Am Chem Soc. 2019 Oct 11. doi: 10.1021/jacs.9b05715. PMID:31603693<ref>PMID:31603693</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6p41" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome C 3D structures|Cytochrome C 3D structures]]
*[[Cytochrome c peroxidase 3D structures|Cytochrome c peroxidase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Saccharomyces cerevisiae S288C]]
[[Category: Crane BR]]
[[Category: Yee EF]]