CATH Classification

Domain Context

CATH Clusters

Superfamily Antioxidant, Horf6; Chain A, domain2
Functional Family Peroxiredoxin

Enzyme Information

1.11.1.15
Peroxiredoxin.
based on mapping to UniProt Q9Y9L0
2 R'-SH + ROOH = R'-S-S-R' + H(2)O + ROH.
-!- Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins. -!- They can be divided into three classes: typical 2-Cys, atypical 2-Cys and 1-Cys peroxiredoxins. -!- The peroxidase reaction comprises two steps centered around a redox- active cysteine called the peroxidatic cysteine. -!- All three peroxiredoxin classes have the first step in common, in which the peroxidatic cysteine attacks the peroxide substrate and is oxidized to S-hydroxycysteine (a sulfenic acid). -!- The second step of the peroxidase reaction, the regeneration of cysteine from S-hydroxycysteine, distinguishes the three peroxiredoxin classes. -!- For typical 2-Cys Prxs, in the second step, the peroxidatic S-hydroxycysteine from one subunit is attacked by the 'resolving' cysteine located in the C-terminus of the second subunit, to form an intersubunit disulfide bond, which is then reduced by one of several cell-specific thiol-containing reductants (R'-SH) (e.g. thioredoxin, AhpF, tryparedoxin or AhpD), completing the catalytic cycle. -!- In the atypical 2-Cys Prxs, both the peroxidatic cysteine and its resolving cysteine are in the same polypeptide, so their reaction forms an intrachain disulfide bond. -!- To recycle the disulfide, known atypical 2-Cys Prxs appear to use thioredoxin as an electron donor. -!- The 1-Cys Prxs conserve only the peroxidatic cysteine, so that its oxidized form is directly reduced to cysteine by the reductant molecule.

UniProtKB Entries (1)

Q9Y9L0
TDXH_AERPE
Aeropyrum pernix K1
Peroxiredoxin

PDB Structure

PDB 3A5W
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Crystal structure of peroxiredoxin from Aeropyrum pernix K1 complexed with its substrate, hydrogen peroxide
Nakamura, T., Kado, Y., Yamaguchi, T., Matsumura, H., Ishikawa, K., Inoue, T.
J.Biochem.