Peroxiredoxin 5: Structure, mechanism and function of the mammalian atypical 2-Cys peroxiredoxin.

Abstract Peroxiredoxin 5 (PRDX5) was the last member to be identified among the six mammalian peroxiredoxins. It is also the unique atypical 2-Cys peroxiredoxin in mammals. Like the other five members, PRDX5 is widely expressed in tissues but differs by its surprisingly large subcellular distribution. In human cells, it has been shown that PRDX5 can be addressed to mitochondria, peroxisomes, the cytosol, and the nucleus. PRDX5 is a peroxidase that can use cytosolic or mitochondrial thioredoxins to reduce alkyl hydroperoxides or peroxynitrite with high rate constants in the 106 to 107 M−1s−1 range, whereas its reaction with hydrogen peroxide is more modest, in the 105 M−1s−1 range. PRDX5 crystal structures confirmed the proposed enzymatic mechanisms based on biochemical data but revealed also some specific unexpected structural features. So far, PRDX5 has been viewed mainly as a cytoprotective antioxidant enzyme acting against endogenous or exogenous peroxide attacks rather than as a redox sensor. Accordin...