4u2s: Difference between revisions
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==Cholesterol oxidase in the reduced state complexed with isopropanol== | |||
<StructureSection load='4u2s' size='340' side='right'caption='[[4u2s]], [[Resolution|resolution]] 1.12Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4u2s]] 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=4U2S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4U2S 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]] 1.12Å</td></tr> | |||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FDA:DIHYDROFLAVINE-ADENINE+DINUCLEOTIDE'>FDA</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=4u2s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4u2s OCA], [https://pdbe.org/4u2s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4u2s RCSB], [https://www.ebi.ac.uk/pdbsum/4u2s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4u2s 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. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Cholesterol oxidase (CO) is a flavoenzyme that catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. The reductive half reaction occurs via a hydride transfer from the substrate to the FAD cofactor. The structures of CO reduced with dithionite under aerobic conditions and in the presence of the substrate 2-propanol under both aerobic and anaerobic conditions are presented. The 1.32 A resolution structure of the dithionite-reduced enzyme reveals a sulfite molecule covalently bound to the FAD cofactor. The isoalloxazine ring system displays a bent structure relative to that of the oxidized enzyme, and alternate conformations of a triad of aromatic residues near to the cofactor are evident. A 1.12 A resolution anaerobically trapped reduced enzyme structure in the presence of 2-propanol does not show a similar bending of the flavin ring system, but does show alternate conformations of the aromatic triad. Additionally, a significant difference electron-density peak is observed within a covalent-bond distance of N5 of the flavin moiety, suggesting that a hydride-transfer event has occurred as a result of substrate oxidation trapping the flavin in the electron-rich reduced state. The hydride transfer generates a tetrahedral geometry about the flavin N5 atom. High-level density-functional theory calculations were performed to correlate the crystallographic findings with the energetics of this unusual arrangement of the flavin moiety. These calculations suggest that strong hydrogen-bond interactions between Gly120 and the flavin N5 centre may play an important role in these structural features. | |||
High-resolution structures of cholesterol oxidase in the reduced state provide insights into redox stabilization.,Golden E, Karton A, Vrielink A Acta Crystallogr D Biol Crystallogr. 2014 Dec 1;70(Pt 12):3155-66. doi:, 10.1107/S139900471402286X. Epub 2014 Nov 22. PMID:25478834<ref>PMID:25478834</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 4u2s" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Cholesterol oxidase|Cholesterol oxidase]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Large Structures]] | |||
[[Category: Streptomyces sp. SA-COO]] | |||
[[Category: Golden EA]] | |||
[[Category: Vrielink A]] | |||
Latest revision as of 03:49, 28 December 2023
Cholesterol oxidase in the reduced state complexed with isopropanolCholesterol oxidase in the reduced state complexed with isopropanol
Structural highlights
FunctionCHOD_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. Publication Abstract from PubMedCholesterol oxidase (CO) is a flavoenzyme that catalyzes the oxidation and isomerization of cholesterol to cholest-4-en-3-one. The reductive half reaction occurs via a hydride transfer from the substrate to the FAD cofactor. The structures of CO reduced with dithionite under aerobic conditions and in the presence of the substrate 2-propanol under both aerobic and anaerobic conditions are presented. The 1.32 A resolution structure of the dithionite-reduced enzyme reveals a sulfite molecule covalently bound to the FAD cofactor. The isoalloxazine ring system displays a bent structure relative to that of the oxidized enzyme, and alternate conformations of a triad of aromatic residues near to the cofactor are evident. A 1.12 A resolution anaerobically trapped reduced enzyme structure in the presence of 2-propanol does not show a similar bending of the flavin ring system, but does show alternate conformations of the aromatic triad. Additionally, a significant difference electron-density peak is observed within a covalent-bond distance of N5 of the flavin moiety, suggesting that a hydride-transfer event has occurred as a result of substrate oxidation trapping the flavin in the electron-rich reduced state. The hydride transfer generates a tetrahedral geometry about the flavin N5 atom. High-level density-functional theory calculations were performed to correlate the crystallographic findings with the energetics of this unusual arrangement of the flavin moiety. These calculations suggest that strong hydrogen-bond interactions between Gly120 and the flavin N5 centre may play an important role in these structural features. High-resolution structures of cholesterol oxidase in the reduced state provide insights into redox stabilization.,Golden E, Karton A, Vrielink A Acta Crystallogr D Biol Crystallogr. 2014 Dec 1;70(Pt 12):3155-66. doi:, 10.1107/S139900471402286X. Epub 2014 Nov 22. PMID:25478834[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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