1n45: Difference between revisions

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 Check<jmol>
    <jmolCheckbox>
-     <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/n4/1n45_consurf.spt"</scriptWhenChecked>
+     <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/n4/1n45_consurf.spt"</scriptWhenChecked>
      <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
      <text>to colour the structure by Evolutionary Conservation</text>
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 <div style="background-color:#fffaf0;">
 == Publication Abstract from PubMed ==
-Heme oxygenase catalyzes the first step in the oxidative degradation of heme. The crystal structure of heme oxygenase-1 (HO-1) reported here reveals a novel helical fold with the heme sandwiched between two helices. The proximal helix provides a heme iron ligand, His 25. Conserved glycines in the distal helix near the oxygen binding site allow close contact between the helix backbone and heme in addition to providing flexibility for substrate binding and product release. Regioselective oxygenation of the alpha-meso heme carbon is due primarily to steric influence of the distal helix.
+Heme oxygenase (HO) catalyzes the degradation of heme to biliverdin. The crystal structure of human HO-1 in complex with heme reveals a novel helical structure with conserved glycines in the distal helix, providing flexibility to accommodate substrate binding and product release (Schuller, D. J., Wilks, A., Ortiz de Montellano, P. R., and Poulos, T. L. (1999) Nat. Struct. Biol. 6, 860-867). To structurally understand the HO catalytic pathway in more detail, we have determined the crystal structure of human apo-HO-1 at 2.1 A and a higher resolution structure of human HO-1 in complex with heme at 1.5 A. Although the 1.5-A heme.HO-1 model confirms our initial analysis based on the 2.08-A model, the higher resolution structure has revealed important new details such as a solvent H-bonded network in the active site that may be important for catalysis. Because of the absence of the heme, the distal and proximal helices that bracket the heme plane in the holo structure move farther apart in the apo structure, thus increasing the size of the active-site pocket. Nevertheless, the relative positioning and conformation of critical catalytic residues remain unchanged in the apo structure compared with the holo structure, but an important solvent H-bonded network is missing in the apoenzyme. It thus appears that the binding of heme and a tightening of the structure around the heme stabilize the solvent H-bonded network required for proper catalysis.
-Crystal structure of human heme oxygenase-1.,Schuller DJ, Wilks A, Ortiz de Montellano PR, Poulos TL Nat Struct Biol. 1999 Sep;6(9):860-7. PMID:10467099<ref>PMID:10467099</ref>
+Comparison of the heme-free and -bound crystal structures of human heme oxygenase-1.,Lad L, Schuller DJ, Shimizu H, Friedman J, Li H, Ortiz de Montellano PR, Poulos TL J Biol Chem. 2003 Mar 7;278(10):7834-43. Epub 2002 Dec 24. PMID:12500973<ref>PMID:12500973</ref>
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
 <div class="pdbe-citations 1n45" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Heme oxygenase|Heme oxygenase]]
 == References ==
 <references/>