View source for 1ep8


==CRYSTAL STRUCTURE OF A MUTATED THIOREDOXIN, D30A, FROM CHLAMYDOMONAS REINHARDTII==
<StructureSection load='1ep8' size='340' side='right'caption='[[1ep8]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1ep8]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Chlamydomonas_reinhardtii Chlamydomonas reinhardtii]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EP8 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EP8 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]] 2.2&#8491;</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=1ep8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1ep8 OCA], [https://pdbe.org/1ep8 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1ep8 RCSB], [https://www.ebi.ac.uk/pdbsum/1ep8 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1ep8 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/TRXH_CHLRE TRXH_CHLRE] Participates in various redox reactions through the reversible oxidation of the active center dithiol to a disulfide. The H form is known to activate a number of cytosolic enzymes.
== 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/ep/1ep8_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=1ep8 ConSurf].
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== Publication Abstract from PubMed ==
Thioredoxins are ubiquitous proteins which catalyse the reduction of disulphide bridges on target proteins. The catalytic mechanism proceeds via a mixed disulphide intermediate whose breakdown should be enhanced by the involvement of a conserved buried residue, Asp-30, as a base catalyst towards residue Cys-39. We report here the crystal structure of wild-type and D30A mutant thioredoxin h from Chlamydomonas reinhardtii, which constitutes the first crystal structure of a cytosolic thioredoxin isolated from a eukaryotic plant organism. The role of residue Asp-30 in catalysis has been revisited since the distance between the carboxylate OD1 of Asp-30 and the sulphur SG of Cys-39 is too great to support the hypothesis of direct proton transfer. A careful analysis of all available crystal structures reveals that the relative positioning of residues Asp-30 and Cys-39 as well as hydrophobic contacts in the vicinity of residue Asp-30 do not allow a conformational change sufficient to bring the two residues close enough for a direct proton transfer. This suggests that protonation/deprotonation of Cys-39 should be mediated by a water molecule. Molecular-dynamics simulations, carried out either in vacuo or in water, as well as proton-inventory experiments, support this hypothesis. The results are discussed with respect to biochemical and structural data.

Crystal structure of the wild-type and D30A mutant thioredoxin h of Chlamydomonas reinhardtii and implications for the catalytic mechanism.,Menchise V, Corbier C, Didierjean C, Saviano M, Benedetti E, Jacquot JP, Aubry A Biochem J. 2001 Oct 1;359(Pt 1):65-75. PMID:11563970<ref>PMID:11563970</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Thioredoxin 3D structures|Thioredoxin 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Chlamydomonas reinhardtii]]
[[Category: Large Structures]]
[[Category: Aubry A]]
[[Category: Benedetti E]]
[[Category: Corbier C]]
[[Category: Didierjean C]]
[[Category: Jacquot JP]]
[[Category: Menchise V]]
[[Category: Saviano M]]