5HWI

Crystal structure of selenomethionine labelled gama glutamyl cyclotransferease specific to glutathione from yeast


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.755 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.168 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

ChaC2, an Enzyme for Slow Turnover of Cytosolic Glutathione

Kaur, A.Gautam, R.Srivastava, R.Chandel, A.Kumar, A.Karthikeyan, S.Bachhawat, A.K.

(2017) J. Biol. Chem. 292: 638-651

  • DOI: 10.1074/jbc.M116.727479
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Glutathione degradation plays an important role in glutathione and redox homeostasis, and thus it is imperative to understand the enzymes and the mechanisms involved in glutathione degradation in detail. We describe here ChaC2, a member of the ChaC f ...

    Glutathione degradation plays an important role in glutathione and redox homeostasis, and thus it is imperative to understand the enzymes and the mechanisms involved in glutathione degradation in detail. We describe here ChaC2, a member of the ChaC family of γ-glutamylcyclotransferases, as an enzyme that degrades glutathione in the cytosol of mammalian cells. ChaC2 is distinct from the previously described ChaC1, to which ChaC2 shows ∼50% sequence identity. Human and mouse ChaC2 proteins purified in vitro show 10-20-fold lower catalytic efficiency than ChaC1, although they showed comparable K m values (K m of 3.7 ± 0.4 mm and k cat of 15.9 ± 1.0 min -1 toward glutathione for human ChaC2; K m of 2.2 ± 0.4 mm and k cat of 225.2 ± 15 min -1 toward glutathione for human ChaC1). The ChaC1 and ChaC2 proteins also shared the same specificity for reduced glutathione, with no activity against either γ-glutamyl amino acids or oxidized glutathione. The ChaC2 proteins were found to be expressed constitutively in cells, unlike the tightly regulated ChaC1. Moreover, lower eukaryotes have a single member of the ChaC family that appears to be orthologous to ChaC2. In addition, we determined the crystal structure of yeast ChaC2 homologue, GCG1, at 1.34 Å resolution, which represents the first structure of the ChaC family of proteins. The catalytic site is defined by a fortuitous benzoic acid molecule bound to the crystal structure. The mechanism for binding and catalytic activity of this new enzyme of glutathione degradation, which is involved in continuous but basal turnover of cytosolic glutathione, is proposed.


    Organizational Affiliation

    the CSIR-Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR), Sector 39A, Chandigarh 160036, India skarthik@imtech.res.in.,From the Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, S.A.S. Nagar, Punjab 140306, India and anand@iisermohali.ac.in.,From the Department of Biological Sciences, Indian Institute of Science Education and Research, Mohali, S.A.S. Nagar, Punjab 140306, India and.,the CSIR-Institute of Microbial Technology, Council of Scientific and Industrial Research (CSIR), Sector 39A, Chandigarh 160036, India.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Glutathione-specific gamma-glutamylcyclotransferase
A
240Saccharomyces cerevisiae (strain ATCC 204508 / S288c)Mutation(s): 4 
Gene Names: GCG1
EC: 4.3.2.7
Find proteins for P32656 (Saccharomyces cerevisiae (strain ATCC 204508 / S288c))
Go to UniProtKB:  P32656
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SIN
Query on SIN

Download SDF File 
Download CCD File 
A
SUCCINIC ACID
C4 H6 O4
KDYFGRWQOYBRFD-UHFFFAOYSA-N
 Ligand Interaction
GOL
Query on GOL

Download SDF File 
Download CCD File 
A
GLYCEROL
GLYCERIN; PROPANE-1,2,3-TRIOL
C3 H8 O3
PEDCQBHIVMGVHV-UHFFFAOYSA-N
 Ligand Interaction
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.755 Å
  • R-Value Free: 0.210 
  • R-Value Work: 0.168 
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 110.545α = 90.00
b = 110.545β = 90.00
c = 42.592γ = 90.00
Software Package:
Software NamePurpose
PHENIXrefinement
HKL-2000data scaling
HKL-2000data reduction
PHENIXphasing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Department of Science and TechnologyIndiaSB/SO/BB/017/2014

Revision History 

  • Version 1.0: 2016-12-14
    Type: Initial release
  • Version 1.1: 2017-01-25
    Type: Database references