1ep7: Difference between revisions
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ep/1ep7_consurf.spt"</scriptWhenChecked> | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/ep/1ep7_consurf.spt"</scriptWhenChecked> | ||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/ | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> | ||
<text>to colour the structure by Evolutionary Conservation</text> | <text>to colour the structure by Evolutionary Conservation</text> | ||
</jmolCheckbox> | </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=1ep7 ConSurf]. | </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=1ep7 ConSurf]. | ||
<div style="clear:both"></div> | <div style="clear:both"></div> | ||
<div style="background-color:#fffaf0;"> | |||
== 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®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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<div class="pdbe-citations 1ep7" style="background-color:#fffaf0;"></div> | |||
==See Also== | ==See Also== | ||
*[[Thioredoxin 3D structures|Thioredoxin 3D structures]] | *[[Thioredoxin 3D structures|Thioredoxin 3D structures]] | ||
== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Latest revision as of 02:56, 21 November 2024
CRYSTAL STRUCTURE OF WT THIOREDOXIN H FROM CHLAMYDOMONAS REINHARDTIICRYSTAL STRUCTURE OF WT THIOREDOXIN H FROM CHLAMYDOMONAS REINHARDTII
Structural highlights
FunctionTRXH_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 Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThioredoxins 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences |
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