View source for 1ozr

==Crystal Structures of the Ferric, Ferrous and Ferrous-NO Forms of the Asp140Ala Mutant of Human Heme Oxygenase-1: Catalytic Implications==
<StructureSection load='1ozr' size='340' side='right' caption='[[1ozr]], [[Resolution|resolution]] 1.74&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ozr]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1OZR OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1OZR FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1oyk|1oyk]], [[1oyl|1oyl]], [[1oze|1oze]], [[1ozl|1ozl]], [[1ozw|1ozw]], [[1p3t|1p3t]], [[1p3u|1p3u]], [[1p3v|1p3v]]</td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">HMOX1 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</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=1ozr FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ozr OCA], [http://www.rcsb.org/pdb/explore.do?structureId=1ozr RCSB], [http://www.ebi.ac.uk/pdbsum/1ozr PDBsum]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/HMOX1_HUMAN HMOX1_HUMAN]] Defects in HMOX1 are the cause of heme oxygenase 1 deficiency (HMOX1D) [MIM:[http://omim.org/entry/614034 614034]]. A disease characterized by impaired stress hematopoiesis, resulting in marked erythrocyte fragmentation and intravascular hemolysis, coagulation abnormalities, endothelial damage, and iron deposition in renal and hepatic tissues. Clinical features include persistent hemolytic anemia, asplenia, nephritis, generalized erythematous rash, growth retardation and hepatomegaly.<ref>PMID:9884342</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/HMOX1_HUMAN HMOX1_HUMAN]] 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/oz/1ozr_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/chain_selection.php?pdb_ID=2ata ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Site-directed mutagenesis studies have shown that Asp140 in both human and rat heme oxygenase-1 is critical for enzyme activity. Here, we report the D140A mutant crystal structure in the Fe(III) and Fe(II) redox states as well as the Fe(II)-NO complex as a model for the Fe(II)-oxy complex. These structures are compared to the corresponding wild-type structures. The mutant and wild-type structures are very similar, except for the distal heme pocket solvent structure. In the Fe(III) D140A mutant one water molecule takes the place of the missing Asp140 carboxylate side-chain and a second water molecule, novel to the mutant, binds in the distal pocket. Upon reduction to the Fe(II) state, the distal helix running along one face of the heme moves closer to the heme in both the wild-type and mutant structures thus tightening the active site. NO binds to both the wild-type and mutant in a bent conformation that orients the NO O atom toward the alpha-meso heme carbon atom. A network of water molecules provides a H-bonded network to the NO ligand, suggesting a possible proton shuttle pathway required to activate dioxygen for catalysis. In the wild-type structure, Asp140 exhibits two conformations, suggesting a dynamic role for Asp140 in shuttling protons from bulk solvent via the water network to the iron-linked oxy complex. On the basis of these structures, we consider why the D140A mutant is inactive as a heme oxygenase but active as a peroxidase.

Crystal structures of the ferric, ferrous, and ferrous-NO forms of the Asp140Ala mutant of human heme oxygenase-1: catalytic implications.,Lad L, Wang J, Li H, Friedman J, Bhaskar B, Ortiz de Montellano PR, Poulos TL J Mol Biol. 2003 Jul 11;330(3):527-38. PMID:12842469<ref>PMID:12842469</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>

==See Also==
*[[Heme oxygenase|Heme oxygenase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Heme oxygenase]]
[[Category: Homo sapiens]]
[[Category: Friedman, J]]
[[Category: Lad, L]]
[[Category: Li, H]]
[[Category: Montellano, P R.Ortiz de]]
[[Category: Poulos, T L]]
[[Category: Wang, J]]
[[Category: Heme degradation]]
[[Category: Oxidoreductase]]