View source for 3zqy


==CYTOCHROME C PRIME FROM ALCALIGENES XYLOSOXIDANS: CARBON MONOOXIDE BOUND L16A VARIANT AT 1.03 A RESOLUTION- NON-RESTRAINT REFINEMENT==
<StructureSection load='3zqy' size='340' side='right'caption='[[3zqy]], [[Resolution|resolution]] 1.03&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3zqy]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Achromobacter_xylosoxidans Achromobacter xylosoxidans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ZQY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ZQY 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]] 1.03&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CMO:CARBON+MONOXIDE'>CMO</scene>, <scene name='pdbligand=HEC:HEME+C'>HEC</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</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=3zqy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3zqy OCA], [https://pdbe.org/3zqy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3zqy RCSB], [https://www.ebi.ac.uk/pdbsum/3zqy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3zqy ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CYCP_ALCXX CYCP_ALCXX] Cytochrome c' is the most widely occurring bacterial c-type cytochrome. Cytochromes c' are high-spin proteins and the heme has no sixth ligand. Their exact function is not known.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Carbon monoxide (CO) is a product of haem metabolism and organisms must evolve strategies to prevent endogenous CO poisoning of haemoproteins. We show that energy costs associated with conformational changes play a key role in preventing irreversible CO binding. AxCYTcp is a member of a family of haem proteins that form stable 5c-NO and 6c-CO complexes but do not form O(2) complexes. Structure of the AxCYTcp-CO complex at 1.25 A resolution shows that CO binds in two conformations moderated by the extent of displacement of the distal residue Leu16 toward the haem 7-propionate. The presence of two CO conformations is confirmed by cryogenic resonance Raman data. The preferred linear Fe-C-O arrangement (170 +/- 8 degrees ) is accompanied by a flip of the propionate from the distal to proximal face of the haem. In the second conformation, the Fe-C-O unit is bent (158 +/- 8 degrees ) with no flip of propionate. The energetic cost of the CO-induced Leu-propionate movements is reflected in a 600 mV (57.9 kJmol(-1)) decrease in haem potential, a value in good agreement with density functional theory calculations. Substitution of Leu by Ala or Gly (structures determined at 1.03 and 1.04 A resolutions) resulted in a haem site that binds CO in the linear mode only and where no significant change in redox potential is observed. Remarkably, these variants were isolated as ferrous 6c-CO complexes, attributable to the observed eight orders of magnitude increase in affinity for CO, including an approximately 10,000-fold decrease in the rate of dissociation. These new findings have wide implications for preventing CO poisoning of gas-binding haem proteins.

Carbon monoxide poisoning is prevented by the energy costs of conformational changes in gas-binding haemproteins.,Antonyuk SV, Rustage N, Petersen CA, Arnst JL, Heyes DJ, Sharma R, Berry NG, Scrutton NS, Eady RR, Andrew CR, Hasnain SS Proc Natl Acad Sci U S A. 2011 Sep 20;108(38):15780-5. Epub 2011 Sep 7. PMID:21900609<ref>PMID:21900609</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3zqy" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome C 3D structures|Cytochrome C 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Achromobacter xylosoxidans]]
[[Category: Large Structures]]
[[Category: Antonyuk SV]]
[[Category: Eady RR]]
[[Category: Hasnain SS]]
[[Category: Rustage N]]