Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 29.00 kDa 
• Atom Count: 2182 
• Modelled Residue Count: 238 
• Deposited Residue Count: 241 
• Unique protein chains: 1

4IS0

Structural Insights into Omega-Class Glutathione Transferases: A Snapshot of Enzyme Reduction and Identification of the Non-Catalytic Ligandin Site.

• PDB DOI: 10.2210/pdb4IS0/pdb

• Classification: TRANSFERASE, OXIDOREDUCTASE
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2013-01-15 Released: 2013-04-24 
• Deposition Author(s): Brock, J., Oakley, A.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.72 Å
• R-Value Free: 0.201 
• R-Value Work: 0.152 
• R-Value Observed: 0.155 

Literature

Structural insights into omega-class glutathione transferases: a snapshot of enzyme reduction and identification of a non-catalytic ligandin site.

Brock, J., Board, P.G., Oakley, A.J.

(2013) PLoS One 8: e60324-e60324

• PubMed: 23593192 
• DOI: 10.1371/journal.pone.0060324
• Primary Citation of Related Structures:  
  4IS0


• PubMed Abstract: 
  

Glutathione transferases (GSTs) are dimeric enzymes containing one active-site per monomer. The omega-class GSTs (hGSTO1-1 and hGSTO2-2 in humans) are homodimeric and carry out a range of reactions including the glutathione-dependant reduction of a range of compounds and the reduction of S-(phenacyl)glutathiones to acetophenones. Both types of reaction result in the formation of a mixed-disulfide of the enzyme with glutathione through the catalytic cysteine (C32). Recycling of the enzyme utilizes a second glutathione molecule and results in oxidized glutathione (GSSG) release. The crystal structure of an active-site mutant (C32A) of the hGSTO1-1 isozyme in complex with GSSG provides a snapshot of the enzyme in the process of regeneration. GSSG occupies both the G (GSH-binding) and H (hydrophobic-binding) sites and causes re-arrangement of some H-site residues. In the same structure we demonstrate the existence of a novel "ligandin" binding site deep within in the dimer interface of this enzyme, containing S-(4-nitrophenacyl)glutathione, an isozyme-specific substrate for hGSTO1-1. The ligandin site, conserved in Omega class GSTs from a range of species, is hydrophobic in nature and may represent the binding location for tocopherol esters that are uncompetitive hGSTO1-1 inhibitors.

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Organizational Affiliation: 

Research School of Chemistry, Australian National University, Canberra, Australian Capital Territory, Australia.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Glutathione S-transferase omega-1	A	241	Homo sapiens	Mutation(s): 1  Gene Names: GSTO1, GSTTLP28 EC: 2.5.1.18 (PDB Primary Data), 1.8.5.1 (PDB Primary Data), 1.20.4.2 (PDB Primary Data)
UniProt & NIH Common Fund Data Resources
Find proteins for P78417 (Homo sapiens) Explore P78417  Go to UniProtKB:  P78417
PHAROS:  P78417

Small Molecules

Ligands 4 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
GDS	D [auth A]	OXIDIZED GLUTATHIONE DISULFIDE C20 H32 N6 O12 S2 YPZRWBKMTBYPTK-BJDJZHNGSA-N
1R4	F [auth A]	L-gamma-glutamyl-S-[2-(4-nitrophenyl)-2-oxoethyl]-L-cysteinylglycine C18 H22 N4 O9 S DFOFAMKKGYFIOO-STQMWFEESA-N
DTT	E [auth A]	2,3-DIHYDROXY-1,4-DITHIOBUTANE C4 H10 O2 S2 VHJLVAABSRFDPM-IMJSIDKUSA-N
SO4	B [auth A], C [auth A]	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.72 Å
• R-Value Free: 0.201 
• R-Value Work: 0.152 
• R-Value Observed: 0.155 
• Space Group: P 3₁ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 57.6	α = 90
b = 57.6	β = 90
c = 140.176	γ = 120

Software Package:

Software Name	Purpose
Blu-Ice	data collection
PHENIX	refinement
MOSFLM	data reduction
SCALA	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2013-01-15 
• Released Date: 2013-04-24 
Deposition Author(s): Brock, J., Oakley, A.J.

Revision History  

• Version 1.0: 2013-04-24
  Type: Initial release
  
• Version 1.1: 2013-07-03
  Changes: Database references
• Version 1.2: 2017-11-15
  Changes: Advisory, Refinement description