2VCV

Glutathione transferase A3-3 in complex with glutathione and delta-4- androstene-3-17-dione


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.223 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural Basis for Featuring of Steroid Isomerase Activity in Alpha Class Glutathione Transferases.

Tars, K.Olin, B.Mannervik, B.

(2010) J.Mol.Biol. 397: 332

  • DOI: 10.1016/j.jmb.2010.01.023
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Glutathione transferases (GSTs) are abundant enzymes catalyzing the conjugation of hydrophobic toxic substrates with glutathione. In addition to detoxication, human GST A3-3 displays prominent steroid double-bond isomerase activity; e.g. transforming ...

    Glutathione transferases (GSTs) are abundant enzymes catalyzing the conjugation of hydrophobic toxic substrates with glutathione. In addition to detoxication, human GST A3-3 displays prominent steroid double-bond isomerase activity; e.g. transforming Delta(5)-androstene-3-17-dione into Delta(4)-androstene-3-17-dione (AD). This chemical transformation is a crucial step in the biosynthesis of steroids, such as testosterone and progesterone. In contrast to GST A3-3, the homologous GST A2-2 does not show significant steroid isomerase activity. We have solved the 3D structures of human GSTs A2-2 and A3-3 in complex with AD. In the GST A3-3 crystal structure, AD was bound in an orientation suitable for the glutathione (GSH)-mediated catalysis to occur. In GST A2-2, however, AD was bound in a completely different orientation with its reactive double bond distant from the GSH-binding site. The structures illustrate how a few amino acid substitutions in the active site spectacularly alter the binding mode of the steroid substrate in relation to the conserved catalytic groups and an essentially fixed polypeptide chain conformation. Furthermore, AD did not bind to the GST A2-2-GSH complex. Altogether, these results provide a first-time structural insight into the steroid isomerase activity of any GST and explain the 5000-fold difference in catalytic efficiency between GSTs A2-2 and A3-3. More generally, the structures illustrate how dramatic diversification of functional properties can arise via minimal structural alterations. We suggest a novel structure-based mechanism of the steroid isomerization reaction.


    Organizational Affiliation

    Latvian Biomedical Research and Study Centre, Ratsupites 1, Riga, Latvia, Sweden. kaspars@biomed.lu.lv




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLUTATHIONE S-TRANSFERASE A3
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P
222Homo sapiensMutation(s): 0 
Gene Names: GSTA3
EC: 2.5.1.18
Find proteins for Q16772 (Homo sapiens)
Go to Gene View: GSTA3
Go to UniProtKB:  Q16772
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GSH
Query on GSH

Download SDF File 
Download CCD File 
A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P
GLUTATHIONE
C10 H17 N3 O6 S
RWSXRVCMGQZWBV-WDSKDSINSA-N
 Ligand Interaction
ASD
Query on ASD

Download SDF File 
Download CCD File 
A, B, D, E, F, G, H, I, K, L, P
4-ANDROSTENE-3-17-DIONE
C19 H26 O2
AEMFNILZOJDQLW-QAGGRKNESA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.223 
  • Space Group: P 1
Unit Cell:
Length (Å)Angle (°)
a = 90.177α = 89.76
b = 92.064β = 89.72
c = 113.540γ = 89.73
Software Package:
Software NamePurpose
MOLREPphasing
MOSFLMdata reduction
REFMACrefinement
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-10-28
    Type: Initial release
  • Version 1.1: 2012-02-29
    Type: Advisory, Atomic model, Database references, Derived calculations, Non-polymer description, Structure summary
  • Version 1.2: 2019-05-29
    Type: Data collection, Experimental preparation, Other