1QXH

Crystal Structure of Escherichia coli Thiol Peroxidase in the Oxidized State


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.191 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Crystal structure of Escherichia coli thiol peroxidase in the oxidized state: insights into intramolecular disulfide formation and substrate binding in atypical 2-Cys peroxiredoxins

Choi, J.Choi, S.Choi, J.Cha, M.-K.Kim, I.-H.Shin, W.

(2003) J Biol Chem 278: 49478-49486

  • DOI: 10.1074/jbc.M309015200
  • Primary Citation of Related Structures:  
    1QXH

  • PubMed Abstract: 
  • Thioredoxin-dependent thiol peroxidase (Tpx) from Escherichia coli represents a group of antioxidant enzymes that are widely distributed in pathogenic bacterial species and which belong to the peroxiredoxin (Prx) family. Bacterial Tpxs are unique in ...

    Thioredoxin-dependent thiol peroxidase (Tpx) from Escherichia coli represents a group of antioxidant enzymes that are widely distributed in pathogenic bacterial species and which belong to the peroxiredoxin (Prx) family. Bacterial Tpxs are unique in that the location of the resolving cysteine (CR) is different from those of other Prxs. E. coli Tpx (EcTpx) shows substrate specificity toward alkyl hydroperoxides over H2O2 and is the most potent reductant of alkyl hydroperoxides surpassing AhpC and BCP, the other E. coli Prx members. Here, we present the crystal structure of EcTpx in the oxidized state determined at 2.2-A resolution. The structure revealed that Tpxs are the second type of atypical 2-Cys Prxs with an intramolecular disulfide bond formed between the peroxidatic (CP, Cys61) and resolving (Cys95) cysteine residues. The extraordinarily long N-terminal chain of EcTpx folds into a beta-hairpin making the overall structure very compact. Modeling suggests that, in atypical 2-Cys Prxs, the CR-loop as well as the CP-loop may alternately assume the fully folded or locally unfolded conformation depending on redox states, as does the CP-loop in typical 2-Cys Prxs. EcTpx exists as a dimer stabilized by hydrogen bonds. Its substrate binding site extends to the dimer interface. A modeled structure of the reduced EcTpx in complex with 15-hydroperoxyeicosatetraenoic acid suggests that the size and shape of the binding site are particularly suited for long fatty acid hydroperoxides consistent with its greater reactivity.


    Related Citations: 
    • Crystallization and preliminary X-ray analysis of Escherichia coli p20, a novel thiol peroxidase
      Choi, J., Choi, S., Choi, J., Cha, M.-K., Kim, I.-H., Shin, W.
      (2003) Acta Crystallogr D Biol Crystallogr 59: 1064

    Organizational Affiliation

    School of Chemistry and Center for Molecular Catalysis, Seoul National University, Seoul 151-742, Korea.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Thiol peroxidaseAB167Escherichia coliMutation(s): 0 
EC: 1.11.1 (PDB Primary Data), 1.11.1.24 (UniProt)
Find proteins for P0A862 (Escherichia coli (strain K12))
Explore P0A862 
Go to UniProtKB:  P0A862
Protein Feature View
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.20 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.191 
  • R-Value Observed: 0.191 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 38.654α = 90
b = 58.428β = 90
c = 127.686γ = 90
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SCALEPACKdata scaling
SOLVEphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2004-01-20
    Type: Initial release
  • Version 1.1: 2008-04-29
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance