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 and as sensor of hydrogen peroxide-mediated signaling events. Preferentially eliminates organic peroxides rather than hydrogen peroxide (PubMed:10391912, PubMed:9988687, PubMed:10681558). Relays alkyl hydroperoxides as a signal to the transcription factor CAD1/YAP2 by inducing the formation of intramolecular disulfide bonds in CAD1, which causes its nuclear accumulation and activation (PubMed:20145245). Involved in cellular Mn(2+) homeostasis (PubMed:10635552). [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O Optimum pH is 6.5. Homodimer; disulfide-linked, upon oxidation. By H(2)O(2). Conjugated to URM1, a ubiquitin-like protein. 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 Prx, C(R) is provided by the other dimeric subunit to form an intersubunit disulfide. The disulfide is subsequently reduced by thioredoxin. Present with 16228 molecules/cell in log phase SD medium. Belongs to the peroxiredoxin family. Prx5 subfamily. Biochemical and mutational analysis assigned Cys-120 as the resolving cysteine (C(R)) (PubMed:9888818). However, crystal structures showed that Cys-120 is deeply buried within the protein and revealed formation of a disulfide bond between the peroxidatic cysteine Cys-62 and the therefore more likely C(R) Cys-31 (PubMed:22474296, Ref.21).