View source for 4hfn


==X-ray Crystal Structure of a Ternary Complex of Double Bond Reductase from Nicotiana tabacum==
<StructureSection load='4hfn' size='340' side='right'caption='[[4hfn]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hfn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Nicotiana_tabacum Nicotiana tabacum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4HFN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HFN 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]] 2.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CIY:(2E)-3-(4-HYDROXY-3-METHOXYPHENYL)PROP-2-ENAL'>CIY</scene>, <scene name='pdbligand=NAP:NADP+NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NAP</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=4hfn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hfn OCA], [https://pdbe.org/4hfn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hfn RCSB], [https://www.ebi.ac.uk/pdbsum/4hfn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hfn ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DBR_TOBAC DBR_TOBAC] Reduces the C=C double bonds of alpha, beta unsaturated enones, but has no activity on enones with an endocyclic C=C double-bond. Shows a high specificity for NADPH as the hybrid donor. Substrates are 1-nitrocyclohexene, 2-methylpentenal, trans-cinnamaldehyde, methyl-trans-2-methylcinnamaldehyde, trans-2-nonenal and 1-octen-3-one. Reduced activity with aplha-methyl transcinnamaldehyde, 1-cyclohexene-1-carboxaldehyde, methyl crotonate, (R)-pulegone, and dimethyl itaconate and no activity with maleimides, citral, (5R)- or (5S)-carvone, (S)-perillyl alcohol, and substituted cyclohexenones and cyclopentenones (PubMed:17945329, Ref.3). May also act as a allyl-alcohol dehydrogenase by catalyzing the dehydrogenation of secondary allylic alcohols rather than saturated secondary alcohols. Allyl-alcohol dehydrogenase is specific for the S-stereoisomer of the alcohols (PubMed:11117876).<ref>PMID:11117876</ref> <ref>PMID:17945329</ref> [REFERENCE:3]
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== Publication Abstract from PubMed ==
The application of biocatalysis for the asymmetric reduction of activated C=C is a powerful tool for the manufacture of high-value chemical commodities. The biocatalytic potential of "-ene" reductases from the Old Yellow Enzyme (OYE) family of oxidoreductases is well-known; however, the specificity of these enzymes toward mainly small molecule substrates has highlighted the need to discover "-ene" reductases from different enzymatic classes to broaden industrial applicability. Here, we describe the characterization of a flavin-free double bond reductase from Nicotiana tabacum (NtDBR), which belongs to the leukotriene B4 dehydrogenase (LTD) subfamily of the zinc-independent, medium chain dehydrogenase/reductase superfamily of enzymes. Using steady-state kinetics and biotransformation reactions, we have demonstrated the regio- and stereospecificity of NtDBR against a variety of alpha,beta-unsaturated activated alkenes. In addition to catalyzing the reduction of typical LTD substrates and several classical OYE-like substrates, NtDBR also exhibited complementary activity by reducing non-OYE substrates (i.e., reducing the exocyclic C=C double bond of (R)-pulegone) and in some cases showing an opposite stereopreference in comparison with the OYE family member pentaerythritol tetranitrate (PETN) reductase. This serves to augment classical OYE "-ene" reductase activity and, coupled with its aerobic stability, emphasizes the potential industrial value of NtDBR. Furthermore, we also report the X-ray crystal structures of the holo-, binary NADP(H)-bound, and ternary [NADP(+) and 4-hydroxy-3-methoxycinnamaldehyde (9a)-bound] NtDBR complexes. These will underpin structure-driven site-saturated mutagenesis studies aimed at enhancing the reactivity, stereochemistry, and specificity of this enzyme.

Biocatalytic Asymmetric Alkene Reduction: Crystal Structure and Characterization of a Double Bond Reductase from Nicotiana tabacum.,Mansell DJ, Toogood HS, Waller J, Hughes JM, Levy CW, Gardiner JM, Scrutton NS ACS Catal. 2013 Mar 1;3(3):370-379. doi: 10.1021/cs300709m. Epub 2013 Jan 21. PMID:27547488<ref>PMID:27547488</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 4hfn" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alcohol dehydrogenase 3D structures|Alcohol dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Nicotiana tabacum]]
[[Category: Scrutton NS]]
[[Category: Toogood HS]]