View source for 5mye


==Solution structure of C20S variant of Dehydroascorbate reductase 3A from Populus trichocarpa in complex with dehydroascorbic acid.==
<StructureSection load='5mye' size='340' side='right'caption='[[5mye]]' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5mye]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Populus_trichocarpa Populus trichocarpa]. Full experimental information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5MYE OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5MYE FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Solution NMR</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=UU3:(5R)-5-[(1S)-1,2-BIS(OXIDANYL)ETHYL]OXOLANE-2,3,4-TRIONE'>UU3</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=5mye FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5mye OCA], [https://pdbe.org/5mye PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5mye RCSB], [https://www.ebi.ac.uk/pdbsum/5mye PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5mye ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B9HM36_POPTR B9HM36_POPTR] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Dehydroascorbate reductases (DHARs), enzymes belonging to the GST superfamily, catalyse the GSH-dependent reduction of dehydroascorbate into ascorbate in plants. By maintaining a reduced ascorbate pool, they notably participate to H2O2 detoxification catalysed by ascorbate peroxidases (APXs). Despite this central role, the catalytic mechanism used by DHARs is still not well understood and there is no supportive 3D structure. In this context, we have performed a thorough biochemical and structural analysis of the three poplar DHARs and coupled this to the analysis of their transcript expression patterns and subcellular localizations. The transcripts for these genes are mainly detected in reproductive and green organs and the corresponding proteins are expressed in plastids, in the cytosol and in the nucleus, but not in mitochondria and peroxisomes where ascorbate regeneration is obviously necessary. Comparing the kinetic properties and the sensitivity to GSSG-mediated oxidation of DHAR2 and DHAR3A, exhibiting 1 or 3 cysteinyl residues respectively, we observed that the presence of additional cysteines in DHAR3A modifies the regeneration mechanism of the catalytic cysteine by forming different redox states. Finally, from the 3D structure of DHAR3A solved by NMR, we were able to map the residues important for the binding of both substrates (GSH and DHA), showing that DHAR active site is very selective for DHA recognition and providing further insights into the catalytic mechanism and the roles of the additional cysteines found in some DHARs.

Insights into ascorbate regeneration in plants: investigating the redox and structural properties of dehydroascorbate reductases from Populus trichocarpa.,Lallement PA, Roret T, Tsan P, Gualberto JM, Girardet JM, Didierjean C, Rouhier N, Hecker A Biochem J. 2016 Mar 15;473(6):717-31. doi: 10.1042/BJ20151147. Epub 2015 Dec 23. PMID:26699905<ref>PMID:26699905</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 5mye" style="background-color:#fffaf0;"></div>
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Populus trichocarpa]]
[[Category: Roret T]]
[[Category: Tsan P]]