View source for 2xl6


==Cytochrome c prime from Alcaligenes xylosoxidans: Ferrous R124A variant with bound NO==
<StructureSection load='2xl6' size='340' side='right'caption='[[2xl6]], [[Resolution|resolution]] 1.07&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2xl6]] 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=2XL6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2XL6 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]] 1.07&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HEC:HEME+C'>HEC</scene>, <scene name='pdbligand=NO:NITRIC+OXIDE'>NO</scene>, <scene name='pdbligand=NO3:NITRATE+ION'>NO3</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=2xl6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xl6 OCA], [https://pdbe.org/2xl6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2xl6 RCSB], [https://www.ebi.ac.uk/pdbsum/2xl6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2xl6 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.
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== Publication Abstract from PubMed ==
Hemoproteins play central roles in the formation and utilization of nitric oxide (NO) in cellular signalling, as well as in protection against nitrosative stress. Key to heme-nitrosyl function and reactivity is the Fe coordination number (5 or 6). For 5c-NO complexes, the potential exists for NO to bind on either heme face, as in the microbial cytochrome c' from Alcaligenes xylosoxidans (AxCYTcp), which forms a stable proximal 5c-NO complex via a distal 6c-NO intermediate and a putative dinitrosyl species. Strong parallels between the NO binding kinetics of AxCYTcp, the eukaryotic NO-sensor, soluble guanylate cyclase, and the ferrocytochrome c/cardiolipin complex have led to the suggestion that a distal to proximal NO switch could contribute to the selective ligand responses in gas-sensing hemoproteins. The proximal NO binding site in AxCYTcp is close to a conserved basic (Arg 124) residue that is postulated to modulate NO reactivity. We have replaced Arg 124 by five different amino acids and have determined high-resolution (1.07-1.40A) crystallographic structures with and without NO. These, together with kinetic and resonance Raman data, provide new insights into the mechanism of distal to proximal heme-NO conversion, including the determinants of Fe-His bond scission. The Arg124Ala variant allowed us to determine the structure of an analog of the previously unobserved key 5c-NO distal intermediate species. The very high-resolution structures combined with the extensive spectroscopic and kinetic data have allowed us to provide a fresh insight into heme reactivity towards NO, a reaction that is of wide importance in biology.

Distal to proximal NO conversion in hemoproteins: The role of the proximal pocket.,Hough MA, Antonyuk SV, Barbieri S, Rustage N, McKay AL, Servid AE, Eady RR, Andrew CR, Hasnain SS J Mol Biol. 2010 Nov 9. PMID:21073879<ref>PMID:21073879</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 2xl6" style="background-color:#fffaf0;"></div>

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