<p> This entry represents the C-terminal domain of 1-Cys peroxiredoxin, a member of the peroxiredoxin superfamily which protect cells against membrane oxidation through glutathione (GSH)-dependent reduction of phospholipid hydroperoxides to corresponding alcohols [<cite idref="PUB00022453"/>]. The C-terminal domain is crucial for providing the extra cysteine necessary for dimerisation of the whole molecule. Loss of the enzyme's peroxidase activity is associated with oxidation of the catalytic cysteine found upstream of this domain. Glutathionylation, presumably through its disruption of protein structure, facilitates access for GSH, resulting in spontaneous reduction of the mixed disulphide to the sulphydryl and consequent activation of the enzyme [<cite idref="PUB00044127"/>]. The domain is associated with <db_xref db="INTERPRO" dbkey="IPR000866"/>, which carries the catalytic cysteine. </p>