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
- PubMed: 16213196
- DOI: 10.1016/j.bbapap.2005.09.001
- PubMed Abstract:
- 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
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.
Department of Chemical Sciences, University of Padua, and ICTB, Via Marzolo 1, and Venetian Institute of Molecular Medicine, Via Orus 2, Padua, Italy.