View source for 6gmo


==Plant glutamate cysteine ligase (GCL) in complex with non-reducing GSH (GSM)==
<StructureSection load='6gmo' size='340' side='right'caption='[[6gmo]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6gmo]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Brassica_juncea Brassica juncea]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6GMO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6GMO 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]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=GSM:L-GAMMA-GLUTAMYL-S-METHYLCYSTEINYLGLYCINE'>GSM</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=6gmo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6gmo OCA], [https://pdbe.org/6gmo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6gmo RCSB], [https://www.ebi.ac.uk/pdbsum/6gmo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6gmo ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/GSH1_BRAJU GSH1_BRAJU] Participates in the detoxification process.<ref>PMID:9620267</ref> <ref>PMID:9119067</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Plant gamma-glutamylcysteine ligase (GCL), catalyzing the first and tightly regulated step of glutathione (GSH) biosynthesis, is redox-activated via formation of an intramolecular disulfide bond. In vitro, redox-activation of recombinant GCL protein causes formation of homo-dimers. Here, we have investigated whether dimerization occurs in vivo and if so whether it contributes to redox-activation. FPLC analysis indicated that recombinant redox-activated WT (wild type) AtGCL dissociates into monomers at concentrations below 10(-6) M, i.e. below the endogenous AtGCL concentration in plastids, which was estimated to be in the micromolar range. Thus, dimerization of redox-activated GCL is expected to occur in vivo To determine the possible impact of dimerization on redox-activation, AtGCL mutants were generated in which salt bridges or hydrophobic interactions at the dimer interface were interrupted. WT AtGCL and mutant proteins were analyzed by non-reducing SDS-PAGE to address their redox state and probed by FPLC for dimerization status. Furthermore, their substrate kinetics (K M, V max) were compared. The results indicate that dimer formation is not required for redox-mediated enzyme activation. Also, crystal structure analysis confirmed that dimer formation does not affect binding of GSH as competitive inhibitor. Whether dimerization affects other enzyme properties, e.g. GCL stability in vivo, remains to be investigated.

Plant glutathione biosynthesis revisited: redox-mediated activation of glutamylcysteine ligase does not require homo-dimerization.,Yang Y, Lenherr ED, Gromes R, Wang S, Wirtz M, Hell R, Peskan-Berghofer T, Scheffzek K, Rausch T Biochem J. 2019 Apr 15;476(7):1191-1203. doi: 10.1042/BCJ20190072. PMID:30877193<ref>PMID:30877193</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 6gmo" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Brassica juncea]]
[[Category: Large Structures]]
[[Category: Lenherr ED]]