View source for 1vgi


==Crystal structure of xenon bound rat heme-heme oxygenase-1 complex==
<StructureSection load='1vgi' size='340' side='right'caption='[[1vgi]], [[Resolution|resolution]] 1.90&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1vgi]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Buffalo_rat Buffalo rat]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1VGI OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1VGI FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=FMT:FORMIC+ACID'>FMT</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=XE:XENON'>XE</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1ulx|1ulx]]</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Heme_oxygenase Heme oxygenase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.14.99.3 1.14.99.3] </span></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=1vgi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1vgi OCA], [http://pdbe.org/1vgi PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1vgi RCSB], [http://www.ebi.ac.uk/pdbsum/1vgi PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1vgi ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/HMOX1_RAT HMOX1_RAT]] Heme oxygenase cleaves the heme ring at the alpha methene bridge to form biliverdin. Biliverdin is subsequently converted to bilirubin by biliverdin reductase. Under physiological conditions, the activity of heme oxygenase is highest in the spleen, where senescent erythrocytes are sequestrated and destroyed. 
== 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/vg/1vgi_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=1vgi ConSurf].
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== Publication Abstract from PubMed ==
Heme oxygenase (HO) catalyzes physiological heme degradation using O(2) and reducing equivalents to produce biliverdin, iron, and CO. Notably, the HO reaction proceeds without product inhibition by CO, which is generated in the conversion reaction of alpha-hydroxyheme to verdoheme, although CO is known to be a potent inhibitor of HO and other heme proteins. In order to probe how endogenous CO is released from the reaction site, we collected X-ray diffraction data from a crystal of the CO-bound form of the ferrous heme-HO complex in the dark and under illumination by a red laser at approximately 35 K. The difference Fourier map indicates that the CO ligand is partially photodissociated from the heme and that the photolyzed CO is trapped in a hydrophobic cavity adjacent to the heme pocket. This hydrophobic cavity was occupied also by xenon, which is similar to CO in terms of size and properties. Taking account of the affinity of CO for the ferrous verdoheme-HO complex being much weaker than that for the ferrous heme complex, the CO derived from alpha-hydroxyheme would be trapped preferentially in the hydrophobic cavity but not coordinated to the iron of verdoheme. This structural device would ensure the smooth progression of the subsequent reaction, from verdoheme to biliverdin, which requires O(2) binding to verdoheme.

CO-trapping site in heme oxygenase revealed by photolysis of its co-bound heme complex: mechanism of escaping from product inhibition.,Sugishima M, Sakamoto H, Noguchi M, Fukuyama K J Mol Biol. 2004 Jul 30;341(1):7-13. PMID:15312758<ref>PMID:15312758</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 1vgi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Heme oxygenase 3D structures|Heme oxygenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Buffalo rat]]
[[Category: Heme oxygenase]]
[[Category: Large Structures]]
[[Category: Fukuyama, K]]
[[Category: Noguchi, M]]
[[Category: Sakamoto, H]]
[[Category: Sugishima, M]]
[[Category: Hydrophobic cavity]]
[[Category: Oxidoreductase]]
[[Category: Xenon binding]]