InterPro domain: IPR045020

This subfamily of peroxiredoxin (known as 1-cys PRX) composed of PRXs containing only one conserved cysteine, which serves as the peroxidatic cysteine. They are homodimeric thiol-specific antioxidant (TSA) proteins that confer a protective role in cells by reducing and detoxifying hydrogen peroxide, peroxynitrite, and organic hydroperoxides [ 1 ]. As with all other PRXs, a cysteine sulfenic acid intermediate is formed upon reaction of 1-cys PRX with its substrates. Having no resolving cysteine, the oxidized enzyme is resolved by an external small-molecule or protein reductant such as thioredoxin or glutaredoxin. Similar to typical 2-cys PRX, 1-cys PRX forms a functional dimeric unit with a B-type interface, as well as a decameric structure which is stabilized in the reduced form of the enzyme. Other oligomeric forms, tetramers and hexamers, have also been reported [ 2 , 3 , 4 ]. Mammalian 1-cys PRX is localized cellularly in the cytosol and is expressed at high levels in brain, eye, testes and lung [ 5 ]. The seed-specific plant 1-cys PRXs protect tissues from reactive oxygen species during desiccation and are also called rehydrins [ 5 , 6 ].

1. Biochemical characterization of Toxoplasma gondii 1-Cys peroxiredoxin 2 with mechanistic similarities to typical 2-Cys Prx. Mol Biochem Parasitol 140, 87-96
2. Crystal Structure of AhpE from Mycobacterium tuberculosis, a 1-Cys peroxiredoxin. J. Mol. Biol. 346, 1035-46
3. Activation of the antioxidant enzyme 1-CYS peroxiredoxin requires glutathionylation mediated by heterodimerization with pi GST. Proc. Natl. Acad. Sci. U.S.A. 101, 3780-5
4. 1-Cys peroxiredoxin, a bifunctional enzyme with glutathione peroxidase and phospholipase A2 activities. J Biol Chem 275, 28421-7
5. FePer 1, a gene encoding an evolutionarily conserved 1-Cys peroxiredoxin in buckwheat (Fagopyrum esculentum Moench), is expressed in a seed-specific manner and induced during seed germination. Gene 246, 81-91
6. Plant peroxiredoxins. Annu Rev Plant Biol 54, 93-107