3IG5

Saccharomyces cerevisiae glutamate cysteine ligase in complex with Mg2+ and L-glutamate

Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.183 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history. 


Literature

Mechanistic details of glutathione biosynthesis revealed by crystal structures of Saccharomyces cerevisiae glutamate cysteine ligase.

Biterova, E.I., Barycki, J.J.

(2009) J Biol Chem 284: 32700-32708

  • DOI: 10.1074/jbc.M109.025114
  • Primary Citation of Related Structures:  
    3IG5, 3IG8

  • PubMed Abstract: 

    • Glutathione is a thiol-disulfide exchange peptide critical for buffering oxidative or chemical stress, and an essential cofactor in several biosynthesis and detoxification pathways. The rate-limiting step in its de novo biosynthesis is catalyzed by glutamate cysteine ligase, a broadly expressed enzyme for which limited structural information is available in higher eukaryotic species ...

    Glutathione is a thiol-disulfide exchange peptide critical for buffering oxidative or chemical stress, and an essential cofactor in several biosynthesis and detoxification pathways. The rate-limiting step in its de novo biosynthesis is catalyzed by glutamate cysteine ligase, a broadly expressed enzyme for which limited structural information is available in higher eukaryotic species. Structural data are critical to the understanding of clinical glutathione deficiency, as well as rational design of enzyme modulators that could impact human disease progression. Here, we have determined the structures of Saccharomyces cerevisiae glutamate cysteine ligase (ScGCL) in the presence of glutamate and MgCl(2) (2.1 A; R = 18.2%, R(free) = 21.9%), and in complex with glutamate, MgCl(2), and ADP (2.7 A; R = 19.0%, R(free) = 24.2%). Inspection of these structures reveals an unusual binding pocket for the alpha-carboxylate of the glutamate substrate and an ATP-independent Mg(2+) coordination site, clarifying the Mg(2+) dependence of the enzymatic reaction. The ScGCL structures were further used to generate a credible homology model of the catalytic subunit of human glutamate cysteine ligase (hGCLC). Examination of the hGCLC model suggests that post-translational modifications of cysteine residues may be involved in the regulation of enzymatic activity, and elucidates the molecular basis of glutathione deficiency associated with patient hGCLC mutations.

    Organizational Affiliation: 

    Department of Biochemistry and the Redox Biology Center, University of Nebraska, Lincoln, Nebraska 68588-0664, USA.



Macromolecules
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(by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Glutamate-cysteine ligaseA692Saccharomyces cerevisiaeMutation(s): 0 
Gene Names: GSH1, J0832, YJL101C
EC: 6.3.2.2
Find proteins for P32477 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Explore P32477 
Go to UniProtKB:  P32477
Protein Feature View
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  • Reference Sequence
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
PGE
Query on PGE
Download Ideal Coordinates CCD File 
 D [auth A], E [auth A], F [auth A], G [auth A]TRIETHYLENE GLYCOL
C6 H14 O4
ZIBGPFATKBEMQZ-UHFFFAOYSA-N		 Ligand Interaction
GLU
Query on GLU
Download Ideal Coordinates CCD File 
 B [auth A]GLUTAMIC ACID
C5 H9 N O4
WHUUTDBJXJRKMK-VKHMYHEASA-N		 Ligand Interaction
MG
Query on MG
Download Ideal Coordinates CCD File 
 C [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N		 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
CSO
Query on CSO		AL-PEPTIDE LINKINGC3 H7 N O3 SCYS
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.10 Å
  • R-Value Free: 0.219 
  • R-Value Work: 0.182 
  • R-Value Observed: 0.183 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 117.444α = 90
b = 117.444β = 90
c = 165.363γ = 90
Software Package:
Software NamePurpose
PHENIXmodel building
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHENIXphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2012-12-26
    Changes: Database references