1V4G

Crystal Structure of gamma-Glutamylcysteine Synthetase from Escherichia coli B


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of gamma-glutamylcysteine synthetase: insights into the mechanism of catalysis by a key enzyme for glutathione homeostasis

Hibi, T.Nii, H.Nakatsu, T.Kimura, A.Kato, H.Hiratake, J.Oda, J.

(2004) PROC.NATL.ACAD.SCI.USA 101: 15052-15057

  • DOI: 10.1073/pnas.0403277101
  • Primary Citation of Related Structures:  
  • Also Cited By: 2D33, 2D32

  • PubMed Abstract: 
  • Gamma-glutamylcysteine synthetase (gammaGCS), a rate-limiting enzyme in glutathione biosynthesis, plays a central role in glutathione homeostasis and is a target for development of potential therapeutic agents against parasites and cancer. We have de ...

    Gamma-glutamylcysteine synthetase (gammaGCS), a rate-limiting enzyme in glutathione biosynthesis, plays a central role in glutathione homeostasis and is a target for development of potential therapeutic agents against parasites and cancer. We have determined the crystal structures of Escherichia coli gammaGCS unliganded and complexed with a sulfoximine-based transition-state analog inhibitor at resolutions of 2.5 and 2.1 A, respectively. In the crystal structure of the complex, the bound inhibitor is phosphorylated at the sulfoximido nitrogen and is coordinated to three Mg2+ ions. The cysteine-binding site was identified; it is formed inductively at the transition state. In the unliganded structure, an open space exists around the representative cysteine-binding site and is probably responsible for the competitive binding of glutathione. Upon inhibitor binding, the side chains of Tyr-241 and Tyr-300 turn, forming a hydrogen-bonding triad with the carboxyl group of the inhibitor's cysteine moiety, allowing this moiety to fit tightly into the cysteine-binding site with concomitant accommodation of its side chain into a shallow pocket. This movement is caused by a conformational change of a switch loop (residues 240-249). Based on this crystal structure, the cysteine-binding sites of mammalian and parasitic gammaGCSs were predicted by multiple sequence alignment, although no significant sequence identity exists between the E. coli gammaGCS and its eukaryotic homologues. The identification of this cysteine-binding site provides important information for the rational design of novel gammaGCS inhibitors.


    Related Citations: 
    • Escherichia coli B gamma-glutamylcysteine synthetase: modification, purification, crystallization and preliminary crystallographic analysis
      Hibi, T.,Hisada, H.,Nakatsu, T.,Kato, H.,Oda, J.
      (2002) Acta Crystallogr.,Sect.D 58: 316


    Organizational Affiliation

    Department of Bioscience, Fukui Prefectural University, Fukui 910-1195, Japan.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutamate--cysteine ligase
A, B, C, D
518Escherichia coli (strain K12)Mutation(s): 4 
Gene Names: gshA (gsh-I)
EC: 6.3.2.2
Find proteins for P0A6W9 (Escherichia coli (strain K12))
Go to UniProtKB:  P0A6W9
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
FME
Query on FME
A, B, C, D
L-PEPTIDE LINKINGC6 H11 N O3 SMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.236 
  • R-Value Work: 0.206 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 326.818α = 90.00
b = 326.818β = 90.00
c = 104.726γ = 120.00
Software Package:
Software NamePurpose
MOSFLMdata reduction
REFMACrefinement
SOLVEphasing
CCP4data scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-10-05
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Advisory, Version format compliance