2GTU

LIGAND-FREE HUMAN GLUTATHIONE S-TRANSFERASE M2-2 (E.C.2.5.1.18), MONOCLINIC CRYSTAL FORM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.203 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

The enhanced affinity for thiolate anion and activation of enzyme-bound glutathione is governed by an arginine residue of human Mu class glutathione S-transferases.

Patskovsky, Y.V.Patskovska, L.N.Listowsky, I.

(2000) J.Biol.Chem. 275: 3296-3304


  • PubMed Abstract: 
  • A series of chimeric human Mu class glutathione S-transferases were designed to determine mechanisms by which they activate enzyme-bound glutathione (GSH) for reaction with electrophilic substrates. In view of evidence that the His(107) residue of hG ...

    A series of chimeric human Mu class glutathione S-transferases were designed to determine mechanisms by which they activate enzyme-bound glutathione (GSH) for reaction with electrophilic substrates. In view of evidence that the His(107) residue of hGSTM1a-1a is important for catalysis (Patskovsky, Y. V., Patskovska, L. N., and Listowsky, I. (1999) Biochemistry 38, 1193-1202), the cognate Arg(107) residue of the hGSTM2 subunit was replaced (R107N or R107H) and arginine residues were also incorporated into position 107 of hGSTM1 (H107R) and hGSTM4 (S107R) subunits. The major distinguishing kinetic properties invariably associated with enzymes containing an Arg(107) residue include an inverse dependence of k(cat) on viscosity and lower K(m(GSH values relative to enzymes with other residues at that position. Moreover, affinities for GSH thiolate anion binding are greater for enzymes containing Arg(107))), with K(d) values of 20-50 microM that are consistent with the K(m(GSH values (10-25 microM) obtained by steady-state kinetic analyses. Both thermodynamic and kinetic and data indicate that the Arg(107))) residue is specifically involved in enhancing the binding affinity of GSH thiolate anion relative to that of the protonated form. These enzymes therefore, can be more effective at lower GSH concentrations. Combined mutations indicate that both Arg(107) and Tyr(6) residues are required for thiolate anion formation and stabilization. The three-dimensional structure of ligand-free hGSTM2-2 determined by x-ray crystallography suggests that Arg(107) maintains an electrostatic interaction with the Asp(161) side chain (3 A apart), but is distant from the GSH-binding site. However, an alternative energetically favorable model places the guanidino group 4 A from the sulfur atom of bound GSH. It is suggested therefore, that in solution, motion of the positively charged arginine into the catalytic pocket could provide a counter ion to promote ionization of the sulfhydryl group of GSH, thereby accounting for the observed greater affinity of enzymes containing Arg(107) for binding of thiolate anion.


    Related Citations: 
    • Crystal Structure of Human Class Mu Glutathione Transferase Gstm2-2. Effects of Lattice Packing on Conformational Heterogeneity
      Raghunathan, S.,Chandross, R.J.,Kretsinger, R.H.,Allison, T.J.,Penington, C.J.,Rule, G.S.
      (1994) J.Mol.Biol. 238: 815
    • Expression, Crystallization and Preliminary X-Ray Analysis of Ligand-Free Human Glutathione S-Transferase M2-2
      Patskovska, L.N.,Fedorov, A.A.,Patskovsky, Y.V.,Almo, S.C.,Listowsky, I.
      (1998) Acta Crystallogr.,Sect.D 54: 458
    • Cloning, Expression, and Characterization of a Class-Mu Glutathione Transferase from Human Muscle, the Product of the Gst4 Locus
      Vorachek, W.R.,Pearson, W.R.,Rule, G.S.
      (1991) Proc.Natl.Acad.Sci.USA 88: 4443


    Organizational Affiliation

    Department of Biochemistry, Albert Einstein College of Medicine, Bronx, New York 10461, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLUTATHIONE S-TRANSFERASE
A, B
217Homo sapiensMutation(s): 0 
Gene Names: GSTM2 (GST4)
EC: 2.5.1.18
Find proteins for P28161 (Homo sapiens)
Go to Gene View: GSTM2
Go to UniProtKB:  P28161
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.55 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.203 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 53.909α = 90.00
b = 81.479β = 109.26
c = 55.621γ = 90.00
Software Package:
Software NamePurpose
X-PLORrefinement
XSCALEdata scaling
XDSdata reduction
X-PLORmodel building
X-PLORphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-03-02
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance