3L0H

Crystal Structure Analysis of W21A mutant of human GSTA1-1 in complex with S-hexylglutathione


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.13 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.170 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Stability of the domain interface contributes towards the catalytic function at the H-site of class alpha glutathione transferase A1-1.

Balchin, D.Fanucchi, S.Achilonu, I.Adamson, R.J.Burke, J.Fernandes, M.Gildenhuys, S.Dirr, H.W.

(2010) Biochim.Biophys.Acta 1804: 2228-2233

  • DOI: 10.1016/j.bbapap.2010.09.003

  • PubMed Abstract: 
  • Cytosolic glutathione transferases (GSTs) are major detoxification enzymes in aerobes. Each subunit has two distinct domains and an active site consisting of a G-site for binding GSH and an H-site for an electrophilic substrate. While the active site ...

    Cytosolic glutathione transferases (GSTs) are major detoxification enzymes in aerobes. Each subunit has two distinct domains and an active site consisting of a G-site for binding GSH and an H-site for an electrophilic substrate. While the active site is located at the domain interface, the role of the stability of this interface in the catalytic function of GSTs is poorly understood. Domain 1 of class alpha GSTs has a conserved tryptophan (Trp21) in helix 1 that forms a major interdomain contact with helices 6 and 8 in domain 2. Replacing Trp21 with an alanine is structurally non-disruptive but creates a cavity between helices 1, 6 and 8 thus reducing the packing density and van der Waals contacts at the domain interface. This results in destabilization of the protein and a marked reduction in catalytic activity. While functionality at the G-site is not adversely affected by the W21A mutation, the H-site becomes more accessible to solvent and less favorable for the electrophilic substrate 1-chloro-2,4-dinitrobenzene (CDNB). Not only does the mutation result in a reduction in the energy for stabilizing the transition state formed in the S(N)Ar reaction between the substrates GSH and CDNB, it also compromises the ability of the enzyme to form and stabilize a transition state analogue (Meisenheimer complex) formed between GSH and 1,3,5-trinitrobenzene (TNB). The study demonstrates that the stability of the domain-domain interface plays a role in mediating the catalytic functionality of the active site, particularly the H-site, of class alpha GSTs.


    Organizational Affiliation

    Protein Structure-Function Research Unit, School of Molecular and Cell Biology and the School Chemistry, University of the Witwatersrand, Johannesburg, South Africa.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione S-transferase A1
A, B
222Homo sapiensMutation(s): 1 
Gene Names: GSTA1
EC: 2.5.1.18
Find proteins for P08263 (Homo sapiens)
Go to Gene View: GSTA1
Go to UniProtKB:  P08263
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GTX
Query on GTX

Download SDF File 
Download CCD File 
A, B
S-HEXYLGLUTATHIONE
C16 H30 N3 O6 S
HXJDWCWJDCOHDG-RYUDHWBXSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.13 Å
  • R-Value Free: 0.233 
  • R-Value Work: 0.170 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 100.229α = 90.00
b = 94.980β = 92.63
c = 51.987γ = 90.00
Software Package:
Software NamePurpose
SAINTdata reduction
REFMACrefinement
PDB_EXTRACTdata extraction
SAINTdata scaling
DMphasing
PHASERphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-01-12
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance