Biological Assembly 1  

 3D View: Structure | Electron Density | 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: 28.35 kDa 
• Atom Count: 2221 
• Residue Count: 239 
• Unique protein chains: 1

3VLN

Human Glutathione Transferase O1-1 C32S Mutant in Complex with Ascorbic Acid

• DOI: 10.2210/pdb3VLN/pdb

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


• Deposited: 2011-12-02 Released: 2012-05-16 
• Deposition Author(s): Brock, J., Board, P.G., Oakley, A.J.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free: 0.217 
• R-Value Work: 0.180 
• R-Value Observed: 0.182 

Literature

Structural insights into the dehydroascorbate reductase activity of human omega-class glutathione transferases.

Zhou, H., Brock, J., Liu, D., Board, P.G., Oakley, A.J.

(2012) J Mol Biol 420: 190-203

• PubMed: 22522127 
• DOI: 10.1016/j.jmb.2012.04.014
• Primary Citation of Related Structures:  
  3Q18, 3Q19, 3VLN, 3QAG


• PubMed Abstract: 
  

The reduction of dehydroascorbate (DHA) to ascorbic acid (AA) is a vital cellular function. The omega-class glutathione transferases (GSTs) catalyze several reductive reactions in cellular biochemistry, including DHA reduction. In humans, two isozymes (GSTO1-1 and GSTO2-2) with significant DHA reductase (DHAR) activity are found, sharing 64% sequence identity. While the activity of GSTO2-2 is higher, it is significantly more unstable in vitro. We report the first crystal structures of human GSTO2-2, stabilized through site-directed mutagenesis and determined at 1.9 Å resolution in the presence and absence of glutathione (GSH). The structure of a human GSTO1-1 has been determined at 1.7 Å resolution in complex with the reaction product AA, which unexpectedly binds in the G-site, where the glutamyl moiety of GSH binds. The structure suggests a similar mode of ascorbate binding in GSTO2-2. This is the first time that a non-GSH-based reaction product has been observed in the G-site of any GST. AA stacks against a conserved aromatic residue, F34 (equivalent to Y34 in GSTO2-2). Mutation of Y34 to alanine in GSTO2-2 eliminates DHAR activity. From these structures and other biochemical data, we propose a mechanism of substrate binding and catalysis of DHAR activity.

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Organizational Affiliation: 

John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, 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 (UniProt), 1.20.4.2 (UniProt)
Find proteins for P78417 (Homo sapiens) Explore P78417  Go to UniProtKB:  P78417
NIH Common Fund Data Resources
PHAROS:  P78417 GTEx:  ENSG00000148834

Small Molecules

Ligands 5 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
ASC	A	ASCORBIC ACID C6 H8 O6 CIWBSHSKHKDKBQ-JLAZNSOCSA-N
SO4	A	SULFATE ION O4 S QAOWNCQODCNURD-UHFFFAOYSA-L
GOL	A	GLYCEROL C3 H8 O3 PEDCQBHIVMGVHV-UHFFFAOYSA-N
EDO	A	1,2-ETHANEDIOL C2 H6 O2 LYCAIKOWRPUZTN-UHFFFAOYSA-N
ACT	A	ACETATE ION C2 H3 O2 QTBSBXVTEAMEQO-UHFFFAOYSA-M

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 1.70 Å
• R-Value Free: 0.217 
• R-Value Work: 0.180 
• R-Value Observed: 0.182 
• Space Group: P 3₁ 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 56.918	α = 90
b = 56.918	β = 90
c = 140.511	γ = 120

Software Package:

Software Name	Purpose
Blu-Ice	data collection
REFMAC	refinement
DENZO	data reduction
SCALEPACK	data scaling

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2011-12-02 
• Released Date: 2012-05-16 
Deposition Author(s): Brock, J., Board, P.G., Oakley, A.J.

Revision History 

• Version 1.0: 2012-05-16
  Type: Initial release
  
• Version 1.1: 2013-06-26
  Changes: Database references
• Version 1.2: 2017-11-22
  Changes: Advisory, Refinement description
• Version 1.3: 2020-07-29
  Type: Remediation
  Reason: Carbohydrate remediation
  Changes: Data collection, Database references, Derived calculations