3O76

1.8 Angstroms molecular structure of mouse liver glutathione S-transferase mutant C47A complexed with S-(P-nitrobenzyl)glutathione


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 

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Ligand Structure Quality Assessment 


This is version 1.2 of the entry. See complete history


Literature

Site-directed mutagenesis of mouse glutathione transferase P1-1 unlocks masked cooperativity, introduces a novel mechanism for 'ping pong' kinetic behaviour, and provides further structural evidence for participation of a water molecule in proton abstraction from glutathione.

McManus, G.Costa, M.Canals, A.Coll, M.Mantle, T.J.

(2011) FEBS J 278: 273-281

  • DOI: https://doi.org/10.1111/j.1742-4658.2010.07944.x
  • Primary Citation of Related Structures:  
    3O76

  • PubMed Abstract: 

    Mouse liver glutathione transferase P1-1 has three cysteine residues at positions 14, 47 and 169. We have constructed the single, double and triple cysteine to alanine mutants to define the behaviour of all three thiols. We confirm that C47 is the 'fast' thiol (pK 7.4), and define C169 as the alkaline reactive residue with a pK(a) of 8.6. Only a small proportion of C14 is reactive with 5,5'-dithiobis-(2-nitrobenoic acid) (DTNB) at pH 9 in the C47A/C169A double mutant. The native enzyme and the C169A mutant exhibited Michaelis-Menten kinetics, but all other thiol to alanine mutants exhibited sigmoidal kinetics to varying degrees. The C169A mutant exhibited 'ping pong' kinetics, consistent with a mechanism whereby liberation of a proton from a reduced enzyme-glutathione (GSH) complex to form an enzyme-GS(-) (unprotonated) complex is essentially irreversible. Intriguingly, similar behaviour has recently been reported for a mutant of the yeast prion Ure2p. This cooperative behaviour is 'mirrored' in the crystal structure of the C47A mutant, which binds the p-nitrobenzyl moiety of p-nitrobenzyglutathione in distinct orientations in the two crystallographic subunits. The asymmetry seen in this structure for product binding is associated with absence of a water molecule W0 in the standard wild-type conformation of product binding that is clearly identifiable in the new structure, which may represent a structural model for binding of incoming GSH prior to displacement of W0. Elimination of W0 as a hydroxonium ion may be the mechanism for the initial proton extrusion from the active site.


  • Organizational Affiliation

    School of Biochemistry and Immunology, Trinity College, Dublin, Ireland. gjmcmanus@gmail.com


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Glutathione S-transferase P 1
A, B
209Mus musculusMutation(s): 1 
Gene Names: Gstp1Gstpib
EC: 2.5.1.18
UniProt
Find proteins for P19157 (Mus musculus)
Explore P19157 
Go to UniProtKB:  P19157
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP19157
Sequence Annotations
Expand
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
GTB
Query on GTB

Download Ideal Coordinates CCD File 
C [auth A],
D [auth B]
S-(P-NITROBENZYL)GLUTATHIONE
C17 H22 N4 O8 S
OAWORKDPTSAMBZ-STQMWFEESA-N
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.77 Å
  • R-Value Free: 0.223 
  • R-Value Work: 0.197 
  • R-Value Observed: 0.199 
  • Space Group: P 43 21 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 60.612α = 90
b = 60.612β = 90
c = 233.888γ = 90
Software Package:
Software NamePurpose
MAR345dtbdata collection
AMoREphasing
REFMACrefinement
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

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Ligand Structure Quality Assessment 


Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2011-06-15
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2023-09-06
    Changes: Data collection, Database references, Derived calculations, Refinement description