Crystal structure of a novel human peroxidase enzyme at 2.0 A resolution.
Hydrogen peroxide (H2O2) has been implicated recently as an intracellular messenger that affects cellular processes including protein phosphorylation, transcription and apoptosis. A set of novel peroxidases, named peroxiredoxins (Prx), regulate the intracellular concentration of H2O2 by reducing it in the presence of an appropriate electron donor. The crystal structure of a human Prx enzyme, hORF6, reveals that the protein contains two discrete domains and forms a dimer. The N-terminal domain has a thioredoxin fold and the C-terminal domain is used for dimerization. The active site cysteine (Cys 47), which exists as cysteine-sulfenic acid in the crystal, is located at the bottom of a relatively narrow pocket. The positively charged environment surrounding Cys 47 accounts for the peroxidase activity of the enzyme, which contains no redox cofactors.
Choi
H J
HJ
Division of Protein Engineering, Korea Research Institute of Bioscience and Biotechnology, KIST, Yusong, Taejon, South Korea.
Kang
S W
SW
Yang
C H
CH
Rhee
S G
SG
Ryu
S E
SE
D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009195:Peroxidase / Q000737:chemistry*; D011487:Protein Conformation; D017510:Protein Folding; D015398:Signal Transduction; D013879:Thioredoxins / Q000737:chemistry
D013879:Thioredoxins; D009195:Peroxidase