1R4W

Crystal structure of Mitochondrial class kappa glutathione transferase


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Parallel Evolutionary Pathways for Glutathione Transferases: Structure and Mechanism of the Mitochondrial Class Kappa Enzyme rGSTK1-1

Ladner, J.E.Parsons, J.F.Rife, C.L.Gilliland, G.L.Armstrong, R.N.

(2004) Biochemistry 43: 352-361

  • DOI: 10.1021/bi035832z

  • PubMed Abstract: 
  • The class kappa glutathione (GSH) transferase is an enzyme that resides in the mitochondrial matrix. Its relationship to members of the canonical GSH transferase superfamily has remained an enigma. The three-dimensional structure of the class kappa e ...

    The class kappa glutathione (GSH) transferase is an enzyme that resides in the mitochondrial matrix. Its relationship to members of the canonical GSH transferase superfamily has remained an enigma. The three-dimensional structure of the class kappa enzyme from rat (rGSTK1-1) in complex with GSH has been solved by single isomorphous replacement with anomalous scattering at a resolution of 2.5 A. The structure reveals that the enzyme is more closely related to the protein disulfide bond isomerase, dsbA, from Escherichia coli than it is to members of the canonical superfamily. The structures of rGSTK1-1 and the canonical superfamily members indicate that the proteins folds have diverged from a common thioredoxin/glutaredoxin progenitor but did so by different mechanisms. The mitochondrial enzyme, therefore, represents a fourth protein superfamily that supports GSH transferase activity. The thioredoxin domain functions in a manner that is similar to that seen in the canonical enzymes by providing key structural elements for the recognition of GSH. The hydroxyl group of S16 is within hydrogen-bonding distance of the sulfur of bound GSH and is, in part, responsible for the ionization of the thiol in the E*GSH complex (pKa = 6.4 +/- 0.1). Preequilibrium kinetic experiments indicate that the k(on) for GSH is 1 x 10(5) M(-1) s(-1) and k(off) for GS- is approximately 8 s(-1) and relatively slow with respect to turnover with 1-chloro-2, 4-dinitrobenzene (CDNB). As a result, the KM(GSH) (11 mM) is much larger than the apparent Kd(GSH) (90 microM). The active site has a relatively open access channel that is flanked by disordered loops that may explain the relatively high turnover number (280 s(-1) at pH 7.0) toward CDNB. The disordered loops form an extensive contiguous patch on one face of the dimeric enzyme, a fact that suggests that the protein surface may interact with a membrane or other protein partner.


    Organizational Affiliation

    The Center for Advanced Research in Biotechnology of the Maryland Biotechnology Institute and the National Institutes of Standards and Technology, Gudelsky Drive, Rockville, Maryland 20850, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione S-transferase, mitochondrial
A, B, C, D
226Rattus norvegicusGene Names: Gstk1
EC: 2.5.1.18
Find proteins for P24473 (Rattus norvegicus)
Go to UniProtKB:  P24473
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GSH
Query on GSH

Download SDF File 
Download CCD File 
A, B, C, D
GLUTATHIONE
C10 H17 N3 O6 S
RWSXRVCMGQZWBV-WDSKDSINSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
GSHKd: 90000 nM BINDINGMOAD
GSHKd: 90000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.256 
  • R-Value Work: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 65.900α = 90.00
b = 110.790β = 101.96
c = 74.740γ = 90.00
Software Package:
Software NamePurpose
RESOLVEphasing
SCALEPACKdata scaling
CNSrefinement
SOLVEphasing
RESOLVEmodel building

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-02-03
    Type: Initial release
  • Version 1.1: 2008-04-29
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance