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PDBsum entry 2gwd

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protein ligands metals links
Ligase PDB id
2gwd
Jmol
Contents
Protein chain
436 a.a. *
Ligands
ACT ×5
GLU
Metals
_MG
Waters ×245
* Residue conservation analysis
PDB id:
2gwd
Name: Ligase
Title: Crystal structure of plant glutamate cysteine ligase in comp mg2+ and l-glutamate
Structure: Glutamate cysteine ligase. Chain: a. Fragment: glutamate cysteine ligase. Synonym: gamma-glutamylcysteine synthetase, gamma-ecs, gcs. Engineered: yes
Source: Brassica juncea. Organism_taxid: 3707. Gene: gsh1. Expressed in: escherichia coli. Expression_system_taxid: 562.
Resolution:
2.09Å     R-factor:   0.178     R-free:   0.227
Authors: M.Hothorn,A.Wachter,R.Gromes,T.Stuwe,T.Rausch,K.Scheffzek
Key ref:
M.Hothorn et al. (2006). Structural basis for the redox control of plant glutamate cysteine ligase. J Biol Chem, 281, 27557-27565. PubMed id: 16766527 DOI: 10.1074/jbc.M602770200
Date:
04-May-06     Release date:   20-Jun-06    
PROCHECK
Go to PROCHECK summary
 Headers
 References

Protein chain
Pfam   ArchSchema ?
O23736  (GSH1_BRAJU) -  Glutamate--cysteine ligase, chloroplastic
Seq:
Struc:
514 a.a.
436 a.a.
Key:    PfamA domain  PfamB domain  Secondary structure  CATH domain

 Enzyme reactions 
   Enzyme class: E.C.6.3.2.2  - Glutamate--cysteine ligase.
[IntEnz]   [ExPASy]   [KEGG]   [BRENDA]
      Reaction: ATP + L-glutamate + L-cysteine = ADP + phosphate + gamma-L-glutamyl-L- cysteine
ATP
+
L-glutamate
Bound ligand (Het Group name = GLU)
corresponds exactly
+ L-cysteine
= ADP
+ phosphate
+ gamma-L-glutamyl-L- cysteine
Molecule diagrams generated from .mol files obtained from the KEGG ftp site
 Gene Ontology (GO) functional annotation 
  GO annot!
  Biological process     cellular modified amino acid biosynthetic process   2 terms 
  Biochemical function     glutamate-cysteine ligase activity     1 term  

 

 
    reference    
 
 
DOI no: 10.1074/jbc.M602770200 J Biol Chem 281:27557-27565 (2006)
PubMed id: 16766527  
 
 
Structural basis for the redox control of plant glutamate cysteine ligase.
M.Hothorn, A.Wachter, R.Gromes, T.Stuwe, T.Rausch, K.Scheffzek.
 
  ABSTRACT  
 
Glutathione (GSH) plays a crucial role in plant metabolism and stress response. The rate-limiting step in the biosynthesis of GSH is catalyzed by glutamate cysteine ligase (GCL) the activity of which is tightly regulated. The regulation of plant GCLs is poorly understood. The crystal structure of substrate-bound GCL from Brassica juncea at 2.1-A resolution reveals a plant-unique regulatory mechanism based on two intramolecular redox-sensitive disulfide bonds. Reduction of one disulfide bond allows a beta-hairpin motif to shield the active site of B. juncea GCL, thereby preventing the access of substrates. Reduction of the second disulfide bond reversibly controls dimer to monomer transition of B. juncea GCL that is associated with a significant inactivation of the enzyme. These regulatory events provide a molecular link between high GSH levels in the plant cell and associated down-regulation of its biosynthesis. Furthermore, known mutations in the Arabidopsis GCL gene affect residues in the close proximity of the active site and thus explain the decreased GSH levels in mutant plants. In particular, the mutation in rax1-1 plants causes impaired binding of cysteine.
 
  Selected figure(s)  
 
Figure 1.
FIGURE 1. Plant GCL shows unique structural features. Front and side views of BjGCL shown in ribbon representation. The central -sheet is depicted in dark blue, the N- and C-terminal helical regions in light blue, and the plant unique arms in dark and light green, respectively. The L-glutamate bound in the active site is represented in bond representation along with the Mg^2+ ion (in cyan). The two disulfide bridges CC1 and CC2 are highlighted in yellow; the -hairpin module is shown in red.
Figure 2.
FIGURE 2. Substrate binding in plant GCL. A, close-up view of the glutamate binding site with the inhibitor BSO (in yellow; sulfur depicted in magenta) in bond representation and including the final 2F[obs] - F[calc] electron density map contoured at 1.5 . Residues reaching from the central -sheet (in blue) to coordinate the Mg^2+ ion (in cyan) are depicted in blue. Residues contributed by the helical arms are shown in light green. B, schematic representation of the inhibitor BSO binding to BjGCL. The LigPlot diagram (50) summarizes key interactions between the BSO ligand and active site residues. Yellow lines, BSO ligand; green lines, BjGCL residues; semicircles with radiating lines; atoms or residues involved in hydrophobic contacts between protein and ligand. C, stereo close-up view of the plant GCL cysteine binding pocket formed by mostly hydrophobic residues (in blue) around the aliphatic side chain of BSO (in light gray). The corresponding secondary structure elements and residues in E. coli GCL (PDB-ID: 1VA6) are shown in orange. D, known mutations in the Arabidopsis GCL gene are in proximity of the substrate binding sites in plant GCL. BjGCL in ribbon representation is shown with BSO and ADP (modeled) in bonds representation (in yellow). Small spheres indicate the positions of residues affected in AtGCL mutant plants (in magenta). Enlarged versions provide models on how the affected residues in rax1-1 and rml1 mutants may interact with GCL substrates. The rax1-1 arginine residue (Arg^220) is shown in a modeled rotamer configuration bringing its guanidinium group in close proximity to the terminal methyl of BSO that corresponds to the sulfhydryl group of cysteine (in green). Interactions are highlighted by dotted lines (in magenta).
 
  The above figures are reprinted by permission from the ASBMB: J Biol Chem (2006, 281, 27557-27565) copyright 2006.  
  Figures were selected by an automated process.  

Literature references that cite this PDB file's key reference

  PubMed id Reference
21370978 H.Takahashi, S.Kopriva, M.Giordano, K.Saito, and R.Hell (2011).
Sulfur assimilation in photosynthetic organisms: molecular functions and regulations of transporters and assimilatory enzymes.
  Annu Rev Plant Biol, 62, 157-184.  
20669021 A.Koprivova, S.T.Mugford, and S.Kopriva (2010).
Arabidopsis root growth dependence on glutathione is linked to auxin transport.
  Plant Cell Rep, 29, 1157-1167.  
20080815 H.Yi, A.Galant, G.E.Ravilious, M.L.Preuss, and J.M.Jez (2010).
Sensing sulfur conditions: simple to complex protein regulatory mechanisms in plant thiol metabolism.
  Mol Plant, 3, 269-279.  
20364282 H.Yi, G.E.Ravilious, A.Galant, H.B.Krishnan, and J.M.Jez (2010).
From sulfur to homoglutathione: thiol metabolism in soybean.
  Amino Acids, 39, 963-978.  
20080670 S.C.Maughan, M.Pasternak, N.Cairns, G.Kiddle, T.Brach, R.Jarvis, F.Haas, J.Nieuwland, B.Lim, C.Müller, E.Salcedo-Sora, C.Kruse, M.Orsel, R.Hell, A.J.Miller, P.Bray, C.H.Foyer, J.A.Murray, A.J.Meyer, and C.S.Cobbett (2010).
Plant homologs of the Plasmodium falciparum chloroquine-resistance transporter, PfCRT, are required for glutathione homeostasis and stress responses.
  Proc Natl Acad Sci U S A, 107, 2331-2336.  
20379751 S.Krueger, A.Donath, M.C.Lopez-Martin, R.Hoefgen, C.Gotor, and H.Hesse (2010).
Impact of sulfur starvation on cysteine biosynthesis in T-DNA mutants deficient for compartment-specific serine-acetyltransferase.
  Amino Acids, 39, 1029-1042.  
20233332 V.Liedschulte, A.Wachter, A.Zhigang, and T.Rausch (2010).
Exploiting plants for glutathione (GSH) production: Uncoupling GSH synthesis from cellular controls results in unprecedented GSH accumulation.
  Plant Biotechnol J, 8, 807-820.  
18812186 C.C.Franklin, D.S.Backos, I.Mohar, C.C.White, H.J.Forman, and T.J.Kavanagh (2009).
Structure, function, and post-translational regulation of the catalytic and modifier subunits of glutamate cysteine ligase.
  Mol Aspects Med, 30, 86-98.  
19239350 C.H.Foyer, G.Noctor, B.Buchanan, K.J.Dietz, and T.Pfannschmidt (2009).
Redox Regulation in Photosynthetic Organisms: Signaling, Acclimation, and Practical Implications.
  Antioxid Redox Signal, 11, 861-905.  
19726687 E.I.Biterova, and J.J.Barycki (2009).
Mechanistic details of glutathione biosynthesis revealed by crystal structures of Saccharomyces cerevisiae glutamate cysteine ligase.
  J Biol Chem, 284, 32700-32708.  
19082776 J.Wu, T.Qu, S.Chen, Z.Zhao, and L.An (2009).
Molecular cloning and characterization of a gamma-glutamylcysteine synthetase gene from Chorispora bungeana.
  Protoplasma, 235, 27-36.  
18648103 A.Figueiredo, A.M.Fortes, S.Ferreira, M.Sebastiana, Y.H.Choi, L.Sousa, B.Acioli-Santos, F.Pessoa, R.Verpoorte, and M.S.Pais (2008).
Transcriptional and metabolic profiling of grape (Vitis vinifera L.) leaves unravel possible innate resistance against pathogenic fungi.
  J Exp Bot, 59, 3371-3381.  
18088327 M.Pasternak, B.Lim, M.Wirtz, R.Hell, C.S.Cobbett, and A.J.Meyer (2008).
Restricting glutathione biosynthesis to the cytosol is sufficient for normal plant development.
  Plant J, 53, 999.  
18444899 N.Rouhier, S.D.Lemaire, and J.P.Jacquot (2008).
The role of glutathione in photosynthetic organisms: emerging functions for glutaredoxins and glutathionylation.
  Annu Rev Plant Biol, 59, 143-166.  
17853356 T.Rausch, R.Gromes, V.Liedschulte, I.Müller, J.Bogs, V.Galovic, and A.Wachter (2007).
Novel insight into the regulation of GSH biosynthesis in higher plants.
  Plant Biol (Stuttg), 9, 565-572.  
The most recent references are shown first. Citation data come partly from CiteXplore and partly from an automated harvesting procedure. Note that this is likely to be only a partial list as not all journals are covered by either method. However, we are continually building up the citation data so more and more references will be included with time.