Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides. [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O Homodimer; disulfide-linked, upon oxidation. 6 homodimers assemble to form a ring-like dodecamer (PubMed:16271889, PubMed:25906064). Interacts with NEK6 (By similarity). Interacts with LRRK2 (By similarity). Interacts with RPS6KC1 (via PX domain) (By similarity). Localizes to early endosomes in a RPS6KC1-dependent manner. Predominantly expressed in adrenal cortex. Also detected in liver, renal cortex and medulla, and adrenal medulla (at protein level). Phosphorylated by LRRK2; phosphorylation reduces perodixase activity. The enzyme can be inactivated by further oxidation of the cysteine sulfenic acid (C(P)-SOH) to sulphinic acid (C(P)-SO2H) and sulphonic acid (C(P)-SO3H) instead of its condensation to a disulfide bond. S-palmitoylated. The active site is a conserved redox-active cysteine residue, the peroxidatic cysteine (C(P)), which makes the nucleophilic attack on the peroxide substrate. The peroxide oxidizes the C(P)-SH to cysteine sulfenic acid (C(P)-SOH), which then reacts with another cysteine residue, the resolving cysteine (C(R)), to form a disulfide bridge. The disulfide is subsequently reduced by an appropriate electron donor to complete the catalytic cycle. In this typical 2-Cys peroxiredoxin, C(R) is provided by the other dimeric subunit to form an intersubunit disulfide. The disulfide is subsequently reduced by thioredoxin. Belongs to the peroxiredoxin family. AhpC/Prx1 subfamily. It is uncertain whether transit peptide cleavage occurs after His-62 or Ala-63. Peptides have been found for both N-termini in roughly equal amounts.