4GSS

HUMAN GLUTATHIONE S-TRANSFERASE P1-1 Y108F MUTANT


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.198 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Multifunctional role of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1. Crystallographic and kinetic studies on the Y108F mutant enzyme.

Lo Bello, M.Oakley, A.J.Battistoni, A.Mazzetti, A.P.Nuccetelli, M.Mazzarese, G.Rossjohn, J.Parker, M.W.Ricci, G.

(1997) Biochemistry 36: 6207-6217

  • DOI: 10.1021/bi962813z

  • PubMed Abstract: 
  • The possible role of the hydroxyl group of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1 has been investigated by means of site-directed mutagenesis, steady-state kinetic analysis, and crystallographic studies. Three repres ...

    The possible role of the hydroxyl group of Tyr 108 in the catalytic mechanism of human glutathione transferase P1-1 has been investigated by means of site-directed mutagenesis, steady-state kinetic analysis, and crystallographic studies. Three representative cosubstrates have been used, i.e. ethacrynic acid, 7-chloro-4-nitrobenz-2-oxa-1,3-diazole, and 1-chloro-2,4-dinitrobenzene. In the presence of ethacrynic acid, the enzyme follows a rapid equilibrium random bi-bi mechanism with a rate-limiting step which occurs after the addition of the substrates and before the release of products. The replacement of Tyr 108 with Phe yields a 14-fold decrease of k(cat), while it does not change appreciably the affinity of the H site for the substrate. In this case, it would appear that the role of the hydroxyl function is to stabilize the transition state for the chemical step, i.e. the Michael addition of GSH to the electrophilic substrate. Crystallographic data are compatible with this conclusion showing the hydroxyl group of Y108 in hydrogen bonding distance of the ketone moiety of ethacrynic acid [Oakley, A. J., Rossjohn, J., Lo Bello, M., Caccuri, A. M., Federici, G., & Parker, M. W. (1997) Biochemistry 36, 576-585]. Moreover, no structural differences are observed between the Y108F mutant and the wild type, suggesting that the removal of the hydroxyl group is solely responsible for the loss of activity. A different involvement of Tyr 108 appears in the catalyzed conjugation of 7-chloro-4-nitrobenz-2-oxa-1,3-diazole with GSH in which the rate-limiting step is of a physical nature, probably a structural transition of the ternary complex. The substitution of Tyr 108 yields an approximately 7-fold increase of k(cat) and a constant k(cat)/Km(NBD-Cl) value. Lack of a critical hydrogen bond between 7-chloro-4-nitrobenz-2-oxa-1,3-diazole and Tyr 108 appears to be the basis of the increased k(cat). In the 1-chloro-2,4-dinitrobenzene/GSH system, no appreciable changes of kinetics parameters are found in the Y108F mutant. We conclude that Y108 has a multifunctional role in glutathione transferase P1-1 catalysis, depending on the nature of the electrophilic cosubstrate.


    Related Citations: 
    • Three-Dimensional Structure of Class Pi Glutathione S-Transferase from Human Placenta in Complex with S-Hexylglutathione at 2.8 A Resolution
      Reinemer, P.,Dirr, H.W.,Ladenstein, R.,Huber, R.,Lo Bello, M.,Federici, G.,Parker, M.W.
      (1992) J.Mol.Biol. 227: 214


    Organizational Affiliation

    Department of Biology, University of Rome Tor Vergata, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GLUTATHIONE S-TRANSFERASE
A, B
209Homo sapiensMutation(s): 1 
Gene Names: GSTP1 (FAEES3, GST3)
EC: 2.5.1.18
Find proteins for P09211 (Homo sapiens)
Go to Gene View: GSTP1
Go to UniProtKB:  P09211
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MES
Query on MES

Download SDF File 
Download CCD File 
A, B
2-(N-MORPHOLINO)-ETHANESULFONIC ACID
C6 H13 N O4 S
SXGZJKUKBWWHRA-UHFFFAOYSA-N
 Ligand Interaction
GTX
Query on GTX

Download SDF File 
Download CCD File 
A, B
S-HEXYLGLUTATHIONE
C16 H30 N3 O6 S
HXJDWCWJDCOHDG-RYUDHWBXSA-O
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.5 Å
  • R-Value Free: 0.262 
  • R-Value Work: 0.198 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 78.486α = 90.00
b = 90.339β = 97.47
c = 68.970γ = 90.00
Software Package:
Software NamePurpose
DENZOdata reduction
X-PLORmodel building
X-PLORrefinement
X-PLORphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1998-01-28
    Type: Initial release
  • Version 1.1: 2008-03-03
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance