View source for 1irm


==Crystal structure of apo heme oxygenase-1==
<StructureSection load='1irm' size='340' side='right'caption='[[1irm]], [[Resolution|resolution]] 2.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1irm]] is a 3 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=1IRM OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1IRM 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]] 2.55&#8491;</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=1irm FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1irm OCA], [https://pdbe.org/1irm PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1irm RCSB], [https://www.ebi.ac.uk/pdbsum/1irm PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1irm ProSAT]</span></td></tr>
</table>
== Function ==
[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 ==
[[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/ir/1irm_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=1irm ConSurf].
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== Publication Abstract from PubMed ==
Heme oxygenase (HO) catalyzes the oxidative cleavage of heme to biliverdin by utilizing O(2) and NADPH. HO (apoHO) was crystallized as twinned P3(2) with three molecules per asymmetric unit, and its crystal structure was determined at 2.55 A resolution. Structural comparison of apoHO and its complex with heme (HO-heme) showed three distinct differences. First, the A helix of the eight alpha-helices (A-H) in HO-heme, which includes the proximal ligand of heme (His25), is invisible in apoHO. In addition, the B helix, a portion of which builds the heme pocket, is shifted toward the heme pocket in apoHO. Second, Gln38 is shifted toward the position where the alpha-meso carbon of heme is located in HO-heme. Nepsilon of Gln38 is hydrogen-bonded to the carbonyl group of Glu29 located at the C-terminal side of the A helix in HO-heme, indicative that this hydrogen bond restrains the angle between the A and B helices in HO-heme. Third, the amide group of Gly143 in the F helix is directed outward from the heme pocket in apoHO, whereas it is directed toward the distal ligand of heme in HO-heme. This means that the F helix around Gly143 must change its conformation to accommodate heme binding. The apoHO structure has the characteristic that the helix on one side of the heme pocket fluctuates, whereas the rest of the structure is similar to that of HO-heme, as observed in such hemoproteins as myoglobin and cytochromes b(5) and b(562). These structural features of apoHO suggest that the orientation of the proximal helix and the position of His25 are fixed upon heme binding.

Crystal structure of rat apo-heme oxygenase-1 (HO-1): mechanism of heme binding in HO-1 inferred from structural comparison of the apo and heme complex forms.,Sugishima M, Sakamoto H, Kakuta Y, Omata Y, Hayashi S, Noguchi M, Fukuyama K Biochemistry. 2002 Jun 11;41(23):7293-300. PMID:12044160<ref>PMID:12044160</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Heme oxygenase 3D structures|Heme oxygenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Rattus norvegicus]]
[[Category: Fukuyama K]]
[[Category: Hayashi S]]
[[Category: Kakuta Y]]
[[Category: Noguchi M]]
[[Category: Omata Y]]
[[Category: Sakamoto H]]
[[Category: Sugishima M]]