Alkyl hydroperoxide reductase subunit C/ Thiol specific antioxidant (IPR000866)

Short name: AhpC/TSA

Overlapping homologous superfamilies

Domain relationships



Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant enzymes that also control cytokine-induced peroxide levels which mediate signal transduction in mammalian cells. Prxs can be regulated by changes to phosphorylation, redox and possibly oligomerisation states. Prxs are divided into three classes: typical 2-Cys Prxs; atypical 2-Cys Prxs; and 1-Cys Prxs. All Prxs share the same basic catalytic mechanism, in which an active-site cysteine (the peroxidatic cysteine) is oxidised to a sulphenic acid by the peroxide substrate. The recycling of the sulphenic acid back to a thiol is what distinguishes the three enzyme classes. Using crystal structures, a detailed catalytic cycle has been derived for typical 2-Cys Prxs, including a model for the redox-regulated oligomeric state proposed to control enzyme activity [PMID: 12517450].

Alkyl hydroperoxide reductase (AhpC) is responsible for directly reducing organic hyperoxides in its reduced dithiol form. Thiol specific antioxidant (TSA) is a physiologically important antioxidant which constitutes an enzymatic defence against sulphur-containing radicals. This family contains AhpC and TSA, as well as related proteins.

GO terms

Biological Process

GO:0055114 oxidation-reduction process

Molecular Function

GO:0016209 antioxidant activity
GO:0016491 oxidoreductase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.