View source for 5kcz


==horse liver S48T alcohol dehydrogenase complexed with NAD and trifluoroethanol==
<StructureSection load='5kcz' size='340' side='right'caption='[[5kcz]], [[Resolution|resolution]] 1.14&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5kcz]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Equus_caballus Equus caballus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5KCZ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5KCZ 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]] 1.14&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ETF:TRIFLUOROETHANOL'>ETF</scene>, <scene name='pdbligand=MRD:(4R)-2-METHYLPENTANE-2,4-DIOL'>MRD</scene>, <scene name='pdbligand=NAJ:NICOTINAMIDE-ADENINE-DINUCLEOTIDE+(ACIDIC+FORM)'>NAJ</scene>, <scene name='pdbligand=ZN:ZINC+ION'>ZN</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=5kcz FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5kcz OCA], [https://pdbe.org/5kcz PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5kcz RCSB], [https://www.ebi.ac.uk/pdbsum/5kcz PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5kcz ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ADH1E_HORSE ADH1E_HORSE] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
The substrate specificities of alcohol dehydrogenases (ADH) are of continuing interest for understanding the physiological functions of these enzymes. Ser-48 and Phe-93 have been identified as important residues in the substrate binding sites of ADHs, but more comprehensive structural and kinetic studies are required. The S48T substitution in horse ADH1E has small effects on kinetic constants and catalytic efficiency (V/Km) with ethanol, but decreases activity with benzyl alcohol and affinity for 2,2,2-trifluoroethanol (TFE) and 2,3,4,5,6-pentafluorobenzyl alcohol (PFB). Nevertheless, atomic resolution crystal structures of the S48T enzyme complexed with NAD+ and TFE or PFB are very similar to the structures for the wild-type enzyme. (The S48A substitution greatly diminishes catalytic activity.) The F93A substitution significantly decreases catalytic efficiency (V/Km) for ethanol and acetaldehyde while increasing activity for larger secondary alcohols and the enantioselectivity for the R-isomer relative to the S-isomer of 2-alcohols. The doubly substituted S48T/F93A enzyme has kinetic constants for primary and secondary alcohols similar to those for the F93A enzyme, but the effect of the S48T substitution is to decrease V/Km for (S)-2-alcohols without changing V/Km for (R)-2-alcohols. Thus, the S48T/F93A substitutions invert the enantioselectivity for alcohol oxidation, increasing the R/S ratio by 10, 590, and 200-fold for 2-butanol, 2-octanol, and sec-phenethyl alcohol, respectively. Transient kinetic studies and simulations of the ordered bi bi mechanism for the oxidation of the 2-butanols by the S48T/F93A ADH show that the rate of hydride transfer is increased about 7-fold for both isomers (relative to wild-type enzyme) and that the inversion of enantioselectivity is due to more productive binding for (R)-2-butanol than for (S)-2-butanol in the ternary complex. Molecular modeling suggests that both of the sec-phenethyl alcohols could bind to the enzyme and that dynamics must affect the rates of catalysis.

Inversion of substrate stereoselectivity of horse liver alcohol dehydrogenase by substitutions of Ser-48 and Phe-93.,Kim K, Plapp BV Chem Biol Interact. 2016 Dec 23. pii: S0009-2797(16)30754-2. doi:, 10.1016/j.cbi.2016.12.016. PMID:28025168<ref>PMID:28025168</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5kcz" style="background-color:#fffaf0;"></div>

==See Also==
*[[Alcohol dehydrogenase 3D structures|Alcohol dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Equus caballus]]
[[Category: Large Structures]]
[[Category: Plapp BV]]