3cxu: Difference between revisions
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< | ==Structure of a Y149F mutant of epoxide hydrolase from Solanum tuberosum== | ||
<StructureSection load='3cxu' size='340' side='right'caption='[[3cxu]], [[Resolution|resolution]] 2.00Å' scene=''> | |||
You may | == Structural highlights == | ||
<table><tr><td colspan='2'>[[3cxu]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Solanum_tuberosum Solanum tuberosum]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3CXU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3CXU FirstGlance]. <br> | |||
or | </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=PG4:TETRAETHYLENE+GLYCOL'>PG4</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=3cxu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3cxu OCA], [https://pdbe.org/3cxu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3cxu RCSB], [https://www.ebi.ac.uk/pdbsum/3cxu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3cxu ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/Q41415_SOLTU Q41415_SOLTU] | |||
== 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/cx/3cxu_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=3cxu ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
A putative proton wire in potato soluble epoxide hydrolase 1, StEH1, was identified and investigated by means of site-directed mutagenesis, steady-state kinetic measurements, temperature inactivation studies, and X-ray crystallography. The chain of hydrogen bonds includes five water molecules coordinated through backbone carbonyl oxygens of Pro(186), Leu(266), His(269), and the His(153) imidazole. The hydroxyl of Tyr(149) is also an integrated component of the chain, which leads to the hydroxyl of Tyr(154). Available data suggest that Tyr(154) functions as a final proton donor to the anionic alkylenzyme intermediate formed during catalysis. To investigate the role of the putative proton wire, mutants Y149F, H153F, and Y149F/H153F were constructed and purified. The structure of the Y149F mutant was solved by molecular replacement and refined to 2.0 A resolution. Comparison with the structure of wild-type StEH1 revealed only subtle structural differences. The hydroxyl group lost as a result of the mutation was replaced by a water molecule, thus maintaining a functioning hydrogen bond network in the proton wire. All mutants showed decreased catalytic efficiencies with the R,R-enantiomer of trans-stilbene oxide, whereas with the S,S-enantiomer, k (cat)/K (M) was similar or slightly increased compared with the wild-type reactions. k (cat) for the Y149F mutant with either TSO enantiomer was increased; thus the lowered enzyme efficiencies were due to increases in K (M). Thermal inactivation studies revealed that the mutated enzymes were more sensitive to elevated temperatures than the wild-type enzyme. Hence, structural alterations affecting the hydrogen bond chain caused increases in k (cat) but lowered thermostability. | |||
Removal of distal protein-water hydrogen bonds in a plant epoxide hydrolase increases catalytic turnover but decreases thermostability.,Thomaeus A, Naworyta A, Mowbray SL, Widersten M Protein Sci. 2008 Jul;17(7):1275-84. Epub 2008 May 30. PMID:18515642<ref>PMID:18515642</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3cxu" style="background-color:#fffaf0;"></div> | |||
==See Also== | |||
*[[Epoxide hydrolase 3D structures|Epoxide hydrolase 3D structures]] | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | [[Category: Large Structures]] | ||
== | |||
< | |||
[[Category: Solanum tuberosum]] | [[Category: Solanum tuberosum]] | ||
[[Category: Mowbray SL]] | |||
[[Category: Mowbray | [[Category: Naworyta A]] | ||
[[Category: Naworyta | [[Category: Thomaeus A]] | ||
[[Category: Thomaeus | [[Category: Widersten M]] | ||
[[Category: Widersten | |||
Latest revision as of 15:34, 30 August 2023
Structure of a Y149F mutant of epoxide hydrolase from Solanum tuberosumStructure of a Y149F mutant of epoxide hydrolase from Solanum tuberosum
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 PubMedA putative proton wire in potato soluble epoxide hydrolase 1, StEH1, was identified and investigated by means of site-directed mutagenesis, steady-state kinetic measurements, temperature inactivation studies, and X-ray crystallography. The chain of hydrogen bonds includes five water molecules coordinated through backbone carbonyl oxygens of Pro(186), Leu(266), His(269), and the His(153) imidazole. The hydroxyl of Tyr(149) is also an integrated component of the chain, which leads to the hydroxyl of Tyr(154). Available data suggest that Tyr(154) functions as a final proton donor to the anionic alkylenzyme intermediate formed during catalysis. To investigate the role of the putative proton wire, mutants Y149F, H153F, and Y149F/H153F were constructed and purified. The structure of the Y149F mutant was solved by molecular replacement and refined to 2.0 A resolution. Comparison with the structure of wild-type StEH1 revealed only subtle structural differences. The hydroxyl group lost as a result of the mutation was replaced by a water molecule, thus maintaining a functioning hydrogen bond network in the proton wire. All mutants showed decreased catalytic efficiencies with the R,R-enantiomer of trans-stilbene oxide, whereas with the S,S-enantiomer, k (cat)/K (M) was similar or slightly increased compared with the wild-type reactions. k (cat) for the Y149F mutant with either TSO enantiomer was increased; thus the lowered enzyme efficiencies were due to increases in K (M). Thermal inactivation studies revealed that the mutated enzymes were more sensitive to elevated temperatures than the wild-type enzyme. Hence, structural alterations affecting the hydrogen bond chain caused increases in k (cat) but lowered thermostability. Removal of distal protein-water hydrogen bonds in a plant epoxide hydrolase increases catalytic turnover but decreases thermostability.,Thomaeus A, Naworyta A, Mowbray SL, Widersten M Protein Sci. 2008 Jul;17(7):1275-84. Epub 2008 May 30. PMID:18515642[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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