View source for 4idf


==Structure of the Fragaria x ananassa enone oxidoreductase in complex with NADPH and HMF==
<StructureSection load='4idf' size='340' side='right'caption='[[4idf]], [[Resolution|resolution]] 1.55&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4idf]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Fragaria_vesca Fragaria vesca]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4IDF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4IDF 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]] 1.55&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=4XX:4-HYDROXY-5-METHYLFURAN-3(2H)-ONE'>4XX</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=NDP:NADPH+DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NDP</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=4idf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4idf OCA], [https://pdbe.org/4idf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4idf RCSB], [https://www.ebi.ac.uk/pdbsum/4idf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4idf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ENOX_FRAVE ENOX_FRAVE] Enone oxidoreductase involved in the biosynthesis of 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF or furaneol), the key flavor compound in strawberries.[UniProtKB:Q84V25]
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The last step in the biosynthetic route to the key strawberry flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone (HDMF) is catalyzed by Fragaria x ananassa enone oxidoreductase (FaEO), earlier putatively assigned as quinone oxidoreductase (FaQR). The ripening-induced enzyme catalyzes the reduction of the exocyclic double bond of the highly reactive precursor 4-hydroxy-5-methyl-2-methylene-3(2H)-furanone (HMMF) in a NAD(P)H-dependent manner. To elucidate the molecular mechanism of this peculiar reaction, we determined the crystal structure of FaEO in six different states or complexes at resolutions of &lt;/=1.6 A, including those with HDMF as well as three distinct substrate analogs. Our crystallographic analysis revealed a monomeric enzyme whose active site is largely determined by the bound NAD(P)H cofactor, which is embedded in a Rossmann-fold. Considering that the quasi-symmetric enolic reaction product HDMF is prone to extensive tautomerization, whereas its precursor HMMF is chemically labile in aqueous solution, we used the asymmetric and more stable surrogate product 2-ethyl-4-hydroxy-5-methyl-3(2H)-furanone (EHMF) and the corresponding substrate (2E)-ethylidene-4-hydroxy-5-methyl-3(2H)-furanone (EDHMF) to study their enzyme complexes as well. Together with deuterium-labeling experiments of EDHMF reduction by [4R-(2)H]NADH and chiral-phase analysis of the reaction product EHMF, our data show that the 4R-hydride of NAD(P)H is transferred to the unsaturated exocyclic C6 carbon of HMMF, resulting in a cyclic achiral enolate intermediate that subsequently becomes protonated, eventually leading to HDMF. Apart from elucidating this important reaction of the plant secondary metabolism our study provides a foundation for protein engineering of enone oxidoreductases and their application in biocatalytic processes.

Structural basis for the enzymatic formation of the key strawberry flavor compound 4-hydroxy-2,5-dimethyl-3(2H)-furanone.,Schiefner A, Sinz Q, Neumaier I, Schwab W, Skerra A J Biol Chem. 2013 Jun 7;288(23):16815-26. doi: 10.1074/jbc.M113.453852. Epub 2013, Apr 15. PMID:23589283<ref>PMID:23589283</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4idf" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Fragaria vesca]]
[[Category: Large Structures]]
[[Category: Schiefner A]]
[[Category: Skerra A]]