View source for 2xlo


==Cytochrome c prime from Alcaligenes xylosoxidans: Ferrous R124E variant with bound NO==
<StructureSection load='2xlo' size='340' side='right' caption='[[2xlo]], [[Resolution|resolution]] 1.24&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2xlo]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/"achromobacter_xylosoxidans"_yabuuchi_and_ohyama_1971 "achromobacter xylosoxidans" yabuuchi and ohyama 1971]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2XLO OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2XLO FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEC:HEME+C'>HEC</scene>, <scene name='pdbligand=NO:NITRIC+OXIDE'>NO</scene></td></tr>
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1cgn|1cgn]], [[1e85|1e85]], [[2xlh|2xlh]], [[2xlm|2xlm]], [[2xl5|2xl5]], [[1cgo|1cgo]], [[1e83|1e83]], [[1e86|1e86]], [[2xl8|2xl8]], [[2xl6|2xl6]], [[1e84|1e84]], [[2xld|2xld]], [[2xle|2xle]]</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2xlo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2xlo OCA], [http://pdbe.org/2xlo PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2xlo RCSB], [http://www.ebi.ac.uk/pdbsum/2xlo PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2xlo ProSAT]</span></td></tr>
</table>
== Function ==
[[http://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 ==
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>
</div>
<div class="pdbe-citations 2xlo" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cytochrome c|Cytochrome c]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Achromobacter xylosoxidans yabuuchi and ohyama 1971]]
[[Category: Antonyuk, S V]]
[[Category: Hasnain, S S]]
[[Category: Hough, M A]]
[[Category: 4-helix bundle]]
[[Category: Electron transport]]
[[Category: Haemoprotein]]