View source for 1axg


==CRYSTAL STRUCTURE OF THE VAL203->ALA MUTANT OF LIVER ALCOHOL DEHYDROGENASE COMPLEXED WITH COFACTOR NAD AND INHIBITOR TRIFLUOROETHANOL SOLVED TO 2.5 ANGSTROM RESOLUTION==
<StructureSection load='1axg' size='340' side='right'caption='[[1axg]], [[Resolution|resolution]] 2.50&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1axg]] is a 4 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=1AXG OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AXG 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]] 2.5&#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=NAD:NICOTINAMIDE-ADENINE-DINUCLEOTIDE'>NAD</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=1axg FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1axg OCA], [https://pdbe.org/1axg PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1axg RCSB], [https://www.ebi.ac.uk/pdbsum/1axg PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1axg ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ADH1E_HORSE ADH1E_HORSE] 
== 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/ax/1axg_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1axg ConSurf].
<div style="clear:both"></div>
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== Publication Abstract from PubMed ==
We present evidence that the size of an active site side chain may modulate the degree of hydrogen tunneling in an enzyme-catalyzed reaction. Primary and secondary kH/kT and kD/kT kinetic isotope effects have been measured for the oxidation of benzyl alcohol catalyzed by horse liver alcohol dehydrogenase at 25 degrees C. As reported in earlier studies, the relationship between secondary kH/kT and kD/kT isotope effects provides a sensitive probe for deviations from classical behavior. In the present work, catalytic efficiency and the extent of hydrogen tunneling have been correlated for the alcohol dehydrogenase-catalyzed hydride transfer among a group of site-directed mutants at position 203. Val-203 interacts with the opposite face of the cofactor NAD+ from the alcohol substrate. The reduction in size of this residue is correlated with diminished tunneling and a two orders of magnitude decrease in catalytic efficiency. Comparison of the x-ray crystal structures of a ternary complex of a high-tunneling (Phe-93 --&gt; Trp) and a low-tunneling (Val-203 --&gt; Ala) mutant provides a structural basis for the observed effects, demonstrating an increase in the hydrogen transfer distance for the low-tunneling mutant. The Val-203 --&gt; Ala ternary complex crystal structure also shows a hyperclosed interdomain geometry relative to the wild-type and the Phe-93 --&gt; Trp mutant ternary complex structures. This demonstrates a flexibility in interdomain movement that could potentially narrow the distance between the donor and acceptor carbons in the native enzyme and may enhance the role of tunneling in the hydride transfer reaction.

A link between protein structure and enzyme catalyzed hydrogen tunneling.,Bahnson BJ, Colby TD, Chin JK, Goldstein BM, Klinman JP Proc Natl Acad Sci U S A. 1997 Nov 25;94(24):12797-802. PMID:9371755<ref>PMID:9371755</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 1axg" 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: Bahnson BJ]]
[[Category: Chin JK]]
[[Category: Colby TD]]
[[Category: Goldstein BM]]
[[Category: Klinman JP]]