1ZOF

Crystal structure of alkyl hydroperoxide-reductase (AhpC) from Helicobacter Pylori


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.236 

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This is version 1.2 of the entry. See complete history

Literature

Crystal structure of alkyl hydroperoxide-reductase (AhpC) from Helicobacter pylori.

Papinutto, E.Windle, H.J.Cendron, L.Battistutta, R.Kelleher, D.Zanotti, G.

(2005) Biochim.Biophys.Acta 1753: 240-246

  • DOI: 10.1016/j.bbapap.2005.09.001

  • PubMed Abstract: 
  • The AhpC protein from H. pylori, a thioredoxin (Trx)-dependent alkyl hydroperoxide-reductase, is a member of the ubiquitous 2-Cys peroxiredoxins family (2-Cys Prxs), a group of thiol-specific antioxidant enzymes. Prxs exert the protective antioxidant ...

    The AhpC protein from H. pylori, a thioredoxin (Trx)-dependent alkyl hydroperoxide-reductase, is a member of the ubiquitous 2-Cys peroxiredoxins family (2-Cys Prxs), a group of thiol-specific antioxidant enzymes. Prxs exert the protective antioxidant role in cells through their peroxidase activity, whereby hydrogen peroxide, peroxynitrite and a wide range of organic hydroperoxides (ROOH) are reduced and detoxified (ROOH + 2e(-)-->ROH + H2O). In this study AhpC has been cloned and overexpressed in E. coli. After purification to homogeneity, crystals of the recombinant protein were grown. They diffract to 2.95 A resolution using synchrotron radiation. The crystal structure of AhpC has been determined using the molecular replacement method (R = 23.6%, R(free) = 25.9%). The model, similar in the overall to other members of the 2-Cys Prx family crystallized as toroide-shaped complexes, consists of a pentameric arrangement of homodimers [(alpha2)5 decamer]. The model of AhpC from H. pylori presents significant differences with respect to other members of the family: apart from some loop regions, alpha5-helix and the C-terminus is shifted, preventing the C-terminal tail of the second subunit from extending toward this region of the molecule. Oligomerization properties of AhpC have been also characterized by gel filtration chromatography.


    Related Citations: 
    • Essential thioredoxin-dependent peroxiredoxin system from Helicobacter pylori: genetic and kinetic characterization
      Baker, L.M.S.,Raudonikiene, A.,Hoffman, P.S.,Poole, L.B.
      (2001) J.Bacteriol. 183: 1961
    • The structure of reduced tryparedoxin peroxidase reveals a decamer and insight into reactivity of 2Cys-peroxiredoxins
      Alphey, M.S.,Bond, C.S.,Tetand, E.,Fairlamb, A.H.,Hunter, W.N.
      (2000) J.Mol.Biol. 300: 903
    • Structure, mechanism and regulation of peroxiredoxins
      Wood, Z.A.,Schroder, E.,Harris, J.R.,Poole, L.B.
      (2003) TRENDS BIOCHEM.SCI. 28: 32


    Organizational Affiliation

    Department of Chemical Sciences, University of Padua, and ICTB, Via Marzolo 1, and Venetian Institute of Molecular Medicine, Via Orus 2, Padua, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
alkyl hydroperoxide-reductase
A, B, C, D, E, F, G, H, I, J
198Helicobacter pylori (strain J99 / ATCC 700824)Mutation(s): 1 
Gene Names: ahpC (tsaA)
EC: 1.11.1.15
Find proteins for P56876 (Helicobacter pylori (strain J99 / ATCC 700824))
Go to UniProtKB:  P56876
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.95 Å
  • R-Value Free: 0.260 
  • R-Value Work: 0.236 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 193.860α = 90.00
b = 138.420β = 125.70
c = 127.540γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
CCP4data scaling
AMoREphasing
MOSFLMdata reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2005-11-29
    Type: Initial release
  • Version 1.1: 2008-04-30
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance