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Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant proteins. They can be divided into three classes: typical 2-Cys, atypical 2-Cys and 1-Cys peroxiredoxins [2]. The peroxidase reaction comprises two steps centred around a redox-active cysteine called the peroxidatic cysteine. All three peroxiredoxin classes have the first step in common, in which the peroxidatic cysteine attacks the peroxide substrate and is oxidized to S-hydroxycysteine (a sulfenic acid) (see mechanism). The second step of the peroxidase reaction, the regeneration of cysteine from S-hydroxycysteine, distinguishes the three peroxiredoxin classes. For typical 2-Cys Prxs, in the second step, the peroxidatic S-hydroxycysteine from one subunit is attacked by the ‘resolving’ cysteine located in the C-terminus of the second subunit, to form an intersubunit disulfide bond, which is then reduced by one of several cell-specific thiol-containing reductants completing the catalytic cycle. In the atypical 2-Cys Prxs, both the peroxidatic cysteine and its resolving cysteine are in the same polypeptide, so their reaction forms an intrachain disulfide bond. To recycle the disulfide, known atypical 2-Cys Prxs appear to use thioredoxin as an electron donor. The 1-Cys Prxs conserve only the peroxidatic cysteine, so its regeneration involves direct interaction with a reductant molecule. Glutaredoxin-dependent peroxiredoxins have been reported from bacteria, fungi, plants, and animals. These enzymes are often able to use an alternative reductant such as thioredoxin or glutathione. |
| References: |
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Rouhier, N., Gelhaye, E. and Jacquot, J.P. Glutaredoxin-dependent peroxiredoxin from poplar: protein-protein interaction and catalytic mechanism. J. Biol. Chem. 277 (2002) 13609–13614. [PMID: 11832487] |
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Wood, Z.A., Schröder, E., Harris, J.R. and Poole, L.B. Structure, mechanism and regulation of peroxiredoxins. Trends Biochem. Sci. 28 (2003) 32–40. [DOI] [PMID: 12517450] |
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Pedrajas, J.R., Padilla, C.A., McDonagh, B. and Barcena, J.A. Glutaredoxin participates in the reduction of peroxides by the mitochondrial 1-CYS peroxiredoxin in Saccharomyces cerevisiae. Antioxid Redox Signal 13 (2010) 249–258. [PMID: 20059400] |
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Hanschmann, E.M., Lonn, M.E., Schutte, L.D., Funke, M., Godoy, J.R., Eitner, S., Hudemann, C. and Lillig, C.H. Both thioredoxin 2 and glutaredoxin 2 contribute to the reduction of the mitochondrial 2-Cys peroxiredoxin Prx3. J. Biol. Chem. 285 (2010) 40699–40705. [PMID: 20929858] |
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Lim, J.G., Bang, Y.J. and Choi, S.H. Characterization of the Vibrio vulnificus 1-Cys peroxiredoxin Prx3 and regulation of its expression by the Fe-S cluster regulator IscR in response to oxidative stress and iron starvation. J. Biol. Chem. 289 (2014) 36263–36274. [PMID: 25398878] |
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Couturier, J., Prosper, P., Winger, A.M., Hecker, A., Hirasawa, M., Knaff, D.B., Gans, P., Jacquot, J.P., Navaza, A., Haouz, A. and Rouhier, N. In the absence of thioredoxins, what are the reductants for peroxiredoxins in Thermotoga maritima. Antioxid Redox Signal 18 (2013) 1613–1622. [PMID: 22866991] |
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