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| | ==Crystal structure of the rat heme oxygenase (HO-1) in complex with heme binding dithioerythritol (DTE)== | | ==Crystal structure of the rat heme oxygenase (HO-1) in complex with heme binding dithioerythritol (DTE)== |
| - | <StructureSection load='3i9u' size='340' side='right' caption='[[3i9u]], [[Resolution|resolution]] 2.25Å' scene=''> | + | <StructureSection load='3i9u' size='340' side='right'caption='[[3i9u]], [[Resolution|resolution]] 2.25Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[3i9u]] 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=3I9U OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3I9U FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[3i9u]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3I9U OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3I9U FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=DTU:(2R,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL'>DTU</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.25Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3i9t|3i9t]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=DTU:(2R,3S)-1,4-DIMERCAPTOBUTANE-2,3-DIOL'>DTU</scene>, <scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene></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=10116 Buffalo rat])</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=3i9u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3i9u OCA], [https://pdbe.org/3i9u PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3i9u RCSB], [https://www.ebi.ac.uk/pdbsum/3i9u PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3i9u ProSAT]</span></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=3i9u FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3i9u OCA], [http://pdbe.org/3i9u PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3i9u RCSB], [http://www.ebi.ac.uk/pdbsum/3i9u PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3i9u ProSAT]</span></td></tr> | + | |
| | </table> | | </table> |
| | == Function == | | == 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. | + | [https://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 == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
| | Check<jmol> | | Check<jmol> |
| | <jmolCheckbox> | | <jmolCheckbox> |
| - | <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i9/3i9u_consurf.spt"</scriptWhenChecked> | + | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i9/3i9u_consurf.spt"</scriptWhenChecked> |
| | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
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| | ==See Also== | | ==See Also== |
| - | *[[Heme oxygenase|Heme oxygenase]] | + | *[[Heme oxygenase 3D structures|Heme oxygenase 3D structures]] |
| | == References == | | == References == |
| | <references/> | | <references/> |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Buffalo rat]] | + | [[Category: Large Structures]] |
| - | [[Category: Heme oxygenase]] | + | [[Category: Rattus norvegicus]] |
| - | [[Category: Ikeda-Saito, M]] | + | [[Category: Ikeda-Saito M]] |
| - | [[Category: Matsui, T]] | + | [[Category: Matsui T]] |
| - | [[Category: Unno, M]] | + | [[Category: Unno M]] |
| - | [[Category: Endoplasmic reticulum]]
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| - | [[Category: Heme]]
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| - | [[Category: Inhibitor]]
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| - | [[Category: Iron]]
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| - | [[Category: Isozyme]]
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| - | [[Category: Metal-binding]]
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| - | [[Category: Microsome]]
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| - | [[Category: Oxidoreductase]]
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| - | [[Category: Phosphoprotein]]
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| Structural highlights
Function
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
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Heme oxygenase (HO) catalyzes the regiospecific conversion of heme to biliverdin, CO, and free iron through three successive oxygenation reactions. HO catalysis is unique in that all three O(2) activations are performed by the substrate itself. This Forum Article overviews our current understanding on the structural and biochemical properties of HO catalysis, especially its first and third oxygenation steps. The HO first step, regiospecific hydroxylation of the porphyrin alpha-meso-carbon atom, is of particular interest because of its sharp contrast to O(2) activation by cytochrome P450. HO was proposed to utilize the FeOOH species but not conventional ferryl hemes as a reactive intermediate for self-hydroxylation. We have succeeded in preparing and characterizing the FeOOH species of HO at low temperature, and our analyses of its reaction, together with mutational and crystallographic studies, reveal that protonation of FeOOH by a distal water molecule is critical in promoting the unique self-hydroxylation. The second oxygenation is a rapid, spontaneous autooxidation of the reactive alpha-meso-hydroxyheme in which the HO enzyme does not play a critical role. Further O(2) activation by verdoheme cleaves its porphyrin macrocycle to form biliverdin and free ferrous iron. This third step has been considered to be a major rate-determining step of HO catalysis to regulate the enzyme activity. Our reaction analysis strongly supports the FeOOH verdoheme as the key intermediate of the ring-opening reaction. This mechanism is very similar to that of the first meso-hydroxylation, and the distal water is suggested to enhance the third step as expected from the similarity. The HO mechanistic studies highlight the catalytic importance of the distal hydrogen-bonding network, and this manuscript also involves our attempts to develop HO inhibitors targeting the unique distal structure.
Dioxygen activation for the self-degradation of heme: reaction mechanism and regulation of heme oxygenase.,Matsui T, Iwasaki M, Sugiyama R, Unno M, Ikeda-Saito M Inorg Chem. 2010 Apr 19;49(8):3602-9. PMID:20380462[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Matsui T, Iwasaki M, Sugiyama R, Unno M, Ikeda-Saito M. Dioxygen activation for the self-degradation of heme: reaction mechanism and regulation of heme oxygenase. Inorg Chem. 2010 Apr 19;49(8):3602-9. PMID:20380462 doi:10.1021/ic901869t
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