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. Has a role in telomere silencing, which is the repression of chromatin structure which leads to a stop in the transcription of nearby genes. Also has a role in the regulation of telomere length. Acts as an alkyl-hydroperoxide reductase in the nucleus during post-diauxic growth. Preferentially reduces alkyl-hydroperoxides rather than hydrogen peroxide. Acts as an antioxidant necessary for stationary phase survival. [thioredoxin]-dithiol + a hydroperoxide = [thioredoxin]-disulfide + an alcohol + H2O Optimum pH is 6.5. Monomer. During the diauxic shift. In response to oxidative stress. 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 atypical 2-Cys peroxiredoxin, C(R) is present in the same subunit to form an intramolecular disulfide. The disulfide is subsequently reduced by thioredoxin. Present with 1840 molecules/cell in log phase SD medium. Belongs to the peroxiredoxin family. BCP/PrxQ subfamily.