View source for 3gyi


==Cholesterol oxidase from Streptomyces sp. N485D mutant (1.0A)==
<StructureSection load='3gyi' size='340' side='right'caption='[[3gyi]], [[Resolution|resolution]] 1.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3gyi]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Streptomyces_sp._SA-COO Streptomyces sp. SA-COO]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3GYI OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3GYI 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]] 1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></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=3gyi FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3gyi OCA], [https://pdbe.org/3gyi PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3gyi RCSB], [https://www.ebi.ac.uk/pdbsum/3gyi PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3gyi ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/CHOD_STRS0 CHOD_STRS0] Bifunctional enzyme that catalyzes the oxidation of the 3-beta-hydroxy group of cholesterol and the isomerization of the double bond of the resulting product.
== 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/gy/3gyi_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=3gyi ConSurf].
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== Publication Abstract from PubMed ==
Cholesterol oxidase is a flavoenzyme that catalyzes the oxidation and isomerization of 3beta-hydroxysteroids. Structural and mutagenesis studies have shown that Asn485 plays a key role in substrate oxidation. The side chain makes an NH...pi interaction with the reduced form of the flavin cofactor. A N485D mutant was constructed to further test the role of the amide group in catalysis. The mutation resulted in a 1800-fold drop in the overall k(cat). Atomic resolution structures were determined for both the N485L and N485D mutants. The structure of the N485D mutant enzyme (at 1.0 A resolution) reveals significant perturbations in the active site. As predicted, Asp485 is oriented away from the flavin moiety, such that any stabilizing interaction with the reduced flavin is abolished. Met122 and Glu361 form unusual hydrogen bonds to the functional group of Asp485 and are displaced from the positions they occupy in the wild-type active site. The overall effect is to disrupt the stabilization of the reduced FAD cofactor during catalysis. Furthermore, a narrow transient channel that is shown to form when the wild-type Asn485 forms the NH...pi interaction with FAD and that has been proposed to function as an access route of molecular oxygen, is not observed in either of the mutant structures, suggesting that the dynamics of the active site are altered.

A hydrogen-bonding network is important for oxidation and isomerization in the reaction catalyzed by cholesterol oxidase.,Lyubimov AY, Chen L, Sampson NS, Vrielink A Acta Crystallogr D Biol Crystallogr. 2009 Nov;65(Pt 11):1222-31. Epub 2009, Oct 22. PMID:19923719<ref>PMID:19923719</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 3gyi" style="background-color:#fffaf0;"></div>

==See Also==
*[[Cholesterol oxidase|Cholesterol oxidase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Streptomyces sp. SA-COO]]
[[Category: Lyubimov AY]]
[[Category: Vrielink A]]