5el8: Difference between revisions
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The | ==The structure of DHAR1 from Arabidopsis thaliana== | ||
<StructureSection load='5el8' size='340' side='right' caption='[[5el8]], [[Resolution|resolution]] 2.30Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[5el8]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5EL8 OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5EL8 FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=GOL:GLYCEROL'>GOL</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=5el8 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5el8 OCA], [http://pdbe.org/5el8 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=5el8 RCSB], [http://www.ebi.ac.uk/pdbsum/5el8 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=5el8 ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[[http://www.uniprot.org/uniprot/DHAR1_ARATH DHAR1_ARATH]] Displays a dual function. As a soluble protein, exhibits glutathione-dependent thiol transferase and dehydroascorbate (DHA) reductase activities. Key component of the ascorbate recycling system. Involved in the redox homeostasis, especially in scavenging of ROS under oxidative stresses, subsequently to biotic or abiotic inducers. As a peripheral membrane protein, could also function as voltage-gated ion channel.<ref>PMID:12077129</ref> <ref>PMID:16262714</ref> <ref>PMID:17267397</ref> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Searches with the human Omega glutathione transferase (GST) identified two outlying groups of the GST superfamily in Arabidopsis thaliana which differed from all other plant GSTs by containing a cysteine in place of a serine at the active site. One group consisted of four genes, three of which encoded active glutathione-dependent dehydroascorbate reductases (DHARs). Two DHARs were predicted to be cytosolic, whereas the other contained a chloroplast targeting peptide. The DHARs were also active as thiol transferases but had no glutathione conjugating activity. Unlike most other GSTs, DHARs were monomeric. The other class of GST comprised two genes termed the Lambda GSTs (GSTLs). The recombinant GSTLs were also monomeric and had glutathione-dependent thiol transferase activity. One GSTL was cytosolic, whereas the other was chloroplast-targeted. When incubated with oxidized glutathione, the putative active site cysteine of the GSTLs and cytosolic DHARs formed mixed disulfides with glutathione, whereas the plastidic DHAR formed an intramolecular disulfide. DHAR S-glutathionylation was consistent with a proposed catalytic mechanism for dehydroascorbate reduction. Roles for the cytosolic DHARs and GSTLs as antioxidant enzymes were also inferred from the induction of the respective genes following exposure to chemicals and oxidative stress. | |||
Functional divergence in the glutathione transferase superfamily in plants. Identification of two classes with putative functions in redox homeostasis in Arabidopsis thaliana.,Dixon DP, Davis BG, Edwards R J Biol Chem. 2002 Aug 23;277(34):30859-69. Epub 2002 Jun 19. PMID:12077129<ref>PMID:12077129</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 5el8" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Lapthorn, A J]] | |||
[[Category: Menault, M]] | |||
[[Category: Roszak, A W]] | |||
[[Category: Arabidopsis thaliana]] | |||
[[Category: Chloride ion channel]] | |||
[[Category: Clic]] | |||
[[Category: Dehydroascobate reductase]] | |||
[[Category: Glutathione s-transferase]] | |||
[[Category: Transferase]] | |||
Revision as of 06:21, 10 December 2016
The structure of DHAR1 from Arabidopsis thalianaThe structure of DHAR1 from Arabidopsis thaliana
Structural highlights
Function[DHAR1_ARATH] Displays a dual function. As a soluble protein, exhibits glutathione-dependent thiol transferase and dehydroascorbate (DHA) reductase activities. Key component of the ascorbate recycling system. Involved in the redox homeostasis, especially in scavenging of ROS under oxidative stresses, subsequently to biotic or abiotic inducers. As a peripheral membrane protein, could also function as voltage-gated ion channel.[1] [2] [3] Publication Abstract from PubMedSearches with the human Omega glutathione transferase (GST) identified two outlying groups of the GST superfamily in Arabidopsis thaliana which differed from all other plant GSTs by containing a cysteine in place of a serine at the active site. One group consisted of four genes, three of which encoded active glutathione-dependent dehydroascorbate reductases (DHARs). Two DHARs were predicted to be cytosolic, whereas the other contained a chloroplast targeting peptide. The DHARs were also active as thiol transferases but had no glutathione conjugating activity. Unlike most other GSTs, DHARs were monomeric. The other class of GST comprised two genes termed the Lambda GSTs (GSTLs). The recombinant GSTLs were also monomeric and had glutathione-dependent thiol transferase activity. One GSTL was cytosolic, whereas the other was chloroplast-targeted. When incubated with oxidized glutathione, the putative active site cysteine of the GSTLs and cytosolic DHARs formed mixed disulfides with glutathione, whereas the plastidic DHAR formed an intramolecular disulfide. DHAR S-glutathionylation was consistent with a proposed catalytic mechanism for dehydroascorbate reduction. Roles for the cytosolic DHARs and GSTLs as antioxidant enzymes were also inferred from the induction of the respective genes following exposure to chemicals and oxidative stress. Functional divergence in the glutathione transferase superfamily in plants. Identification of two classes with putative functions in redox homeostasis in Arabidopsis thaliana.,Dixon DP, Davis BG, Edwards R J Biol Chem. 2002 Aug 23;277(34):30859-69. Epub 2002 Jun 19. PMID:12077129[4] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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