2e2g

Crystal structure of archaeal peroxiredoxin, thioredoxin peroxidase from Aeropyrum pernix K1 (pre-oxidation form)

spinqualitylabelsall models 2e2g, resolution 2.40Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2e2g is a 10 chain structure with sequence from Aeropyrum pernix K1. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 2.4Å Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function TDXH_AERPE Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed The oxidation of thiol groups in proteins is a common event in biochemical processes involving disulfide bond formation and in response to an increased level of reactive oxygen species. It has been widely accepted that the oxidation of a cysteine side chain is initiated by the formation of cysteine sulfenic acid (Cys-SOH). Here, we demonstrate a mechanism of thiol oxidation through a hypervalent sulfur intermediate by presenting crystallographic evidence from an archaeal peroxiredoxin (Prx), the thioredoxin peroxidase from Aeropyrum pernix K1 (ApTPx). The reaction of Prx, which is the reduction of a peroxide, depends on the redox active cysteine side chains. Oxidation by hydrogen peroxide converted the active site peroxidatic Cys-50 of ApTPx to a cysteine sulfenic acid derivative, followed by further oxidation to cysteine sulfinic and sulfonic acids. The crystal structure of the cysteine sulfenic acid derivative was refined to 1.77 A resolution with R(cryst) and R(free) values of 18.8% and 22.0%, respectively. The refined structure, together with quantum chemical calculations, revealed that the sulfenic acid derivative is a type of sulfurane, a hypervalent sulfur compound, and that the S(gamma) atom is covalently linked to the N(delta1) atom of the neighboring His-42. The reaction mechanism is revealed by the hydrogen bond network around the peroxidatic cysteine and the motion of the flexible loop covering the active site and by quantum chemical calculations. This study provides evidence that a hypervalent sulfur compound occupies an important position in biochemical processes. Oxidation of archaeal peroxiredoxin involves a hypervalent sulfur intermediate.,Nakamura T, Yamamoto T, Abe M, Matsumura H, Hagihara Y, Goto T, Yamaguchi T, Inoue T Proc Natl Acad Sci U S A. 2008 Apr 29;105(17):6238-42. Epub 2008 Apr 24. PMID:18436649 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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