Peroxiredoxin, C-terminal
IPR019479
Definition
This entry represents the C-terminal domain of 1-Cys peroxiredoxin. The domain is associated with [interpro:IPR000866], which carries the catalytic cysteine. The C-terminal domain is crucial for dimerisation, providing the additional cysteine residue necessary for the assembly of the functional homodimer. 1-Cys peroxiredoxin is a member of the peroxiredoxin superfamily, which protects cells against membrane oxidation through glutathione (GSH)-dependent reduction of phospholipid hydroperoxides to their corresponding alcohols PMID:9587003. The enzyme's peroxidase activity is lost upon oxidation of the catalytic cysteine located upstream of this domain. Glutathionylation, presumably through disruption of protein structure, facilitates access for GSH, enabling spontaneous reduction of the mixed disulphide to the sulphydryl form and consequent reactivation of the enzyme PMID:15004285. 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 (Ahp) has two subunits, the small AhpC subunit and the large AhpF subunit PMID:30657885. AhpC is responsible for directly reducing organic hydroperoxides in its reduced dithiol form. Thiol specific antioxidant (TSA) is a physiologically important antioxidant which constitutes an enzymatic defence against sulphur-containing radicals and protects the cell against the oxidative stress caused by protein misfolding and aggregation PMID:24424024. This entry contains AhpC and TSA, as well as related proteins.
5 human proteins with this domain
Each is a reviewed human protein in the Seroatlas serome and a potential autoantibody target; this domain groups them into one antibody-relevant category. Every entry links to its own record.
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