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New page: left|200px<br /><applet load="1axe" size="450" color="white" frame="true" align="right" spinBox="true" caption="1axe, resolution 2.0Å" /> '''CRYSTAL STRUCTURE OF ... |
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== | ==CRYSTAL STRUCTURE OF THE ACTIVE-SITE MUTANT PHE93->TRP OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH NAD AND INHIBITOR TRIFLUOROETHANOL== | ||
We present evidence that the size of an active site side chain may | <StructureSection load='1axe' size='340' side='right'caption='[[1axe]], [[Resolution|resolution]] 2.00Å' scene=''> | ||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[1axe]] 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=1AXE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AXE 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]] 2Å</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=1axe FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1axe OCA], [https://pdbe.org/1axe PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1axe RCSB], [https://www.ebi.ac.uk/pdbsum/1axe PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1axe 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/1axe_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.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=1axe ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== 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 --> Trp) and a low-tunneling (Val-203 --> 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 --> Ala ternary complex crystal structure also shows a hyperclosed interdomain geometry relative to the wild-type and the Phe-93 --> 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®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
[[ | <div class="pdbe-citations 1axe" style="background-color:#fffaf0;"></div> | ||
==See Also== | |||
*[[Alcohol dehydrogenase 3D structures|Alcohol dehydrogenase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Equus caballus]] | [[Category: Equus caballus]] | ||
[[Category: | [[Category: Large Structures]] | ||
[[Category: Chin | [[Category: Chin JK]] | ||
[[Category: Colby | [[Category: Colby TD]] | ||
[[Category: Goldstein | [[Category: Goldstein BM]] | ||
Latest revision as of 13:57, 2 August 2023
CRYSTAL STRUCTURE OF THE ACTIVE-SITE MUTANT PHE93->TRP OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH NAD AND INHIBITOR TRIFLUOROETHANOLCRYSTAL STRUCTURE OF THE ACTIVE-SITE MUTANT PHE93->TRP OF HORSE LIVER ALCOHOL DEHYDROGENASE IN COMPLEX WITH NAD AND INHIBITOR TRIFLUOROETHANOL
Structural highlights
FunctionEvolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedWe 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 --> Trp) and a low-tunneling (Val-203 --> 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 --> Ala ternary complex crystal structure also shows a hyperclosed interdomain geometry relative to the wild-type and the Phe-93 --> 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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