3VLN

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.180 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

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

  • DOI: 10.1016/j.jmb.2012.04.014
  • Primary Citation of Related Structures:  

  • 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 isozyme ...

    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.


    Organizational Affiliation

    John Curtin School of Medical Research, Australian National University, Canberra, ACT 0200, Australia.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione S-transferase omega-1
A
241Homo sapiensMutation(s): 1 
Gene Names: GSTO1 (GSTTLP28)
EC: 2.5.1.18
Find proteins for P78417 (Homo sapiens)
Go to Gene View: GSTO1
Go to UniProtKB:  P78417
Small Molecules
Ligands 5 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

Download SDF File 
Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
ACT
Query on ACT

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Download CCD File 
A
ACETATE ION
C2 H3 O2
QTBSBXVTEAMEQO-UHFFFAOYSA-M
 Ligand Interaction
GOL
Query on GOL

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Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
ASC
Query on ASC

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Download CCD File 
A
ASCORBIC ACID
C6 H8 O6
CIWBSHSKHKDKBQ-JLAZNSOCSA-N
 Ligand Interaction
EDO
Query on EDO

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Download CCD File 
A
1,2-ETHANEDIOL
ETHYLENE GLYCOL
C2 H6 O2
LYCAIKOWRPUZTN-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.7 Å
  • R-Value Free: 0.217 
  • R-Value Work: 0.180 
  • Space Group: P 31 2 1
Unit Cell:
Length (Å)Angle (°)
a = 56.918α = 90.00
b = 56.918β = 90.00
c = 140.511γ = 120.00
Software Package:
Software NamePurpose
REFMACrefinement
SCALEPACKdata scaling
DENZOdata reduction
Blu-Icedata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-05-16
    Type: Initial release
  • Version 1.1: 2013-06-26
    Type: Database references
  • Version 1.2: 2017-11-22
    Type: Advisory, Refinement description