IUBMB Enzyme Nomenclature


Accepted name: sulfiredoxin

Reaction: peroxiredoxin-(S-hydroxy-S-oxocysteine) + ATP + 2 R-SH = peroxiredoxin-(S-hydroxycysteine) + ADP + phosphate + R-S-S-R

Other name(s): Srx1; sulphiredoxin; peroxiredoxin-(S-hydroxy-S-oxocysteine) reductase

Systematic name: peroxiredoxin-(S-hydroxy-S-oxocysteine):thiol oxidoreductase [ATP-hydrolysing; peroxiredoxin-(S-hydroxycysteine)-forming]

Comments: In the course of the reaction of EC, peroxiredoxin, its cysteine residue is alternately oxidized to the sulfenic acid, S-hydroxycysteine, and reduced back to cysteine. Occasionally the S-hydroxycysteine residue is further oxidized to the sulfinic acid S-hydroxy-S-oxocysteine, thereby inactivating the enzyme. The reductase provides a mechanism for regenerating the active form of peroxiredoxin, i.e. the peroxiredoxin-(S-hydroxycysteine) form. Apparently the reductase first catalyses the phosphorylation of the -S(O)-OH group by ATP to give -S(O)-O-P, which is attached to the peroxiredoxin by a cysteine residue, forming an -S(O)-S- link between the two enzymes. Attack by a thiol splits this bond, leaving the peroxiredoxin as the sulfenic acid and the reductase as the thiol.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number: 710319-61-2


1. Biteau, B., Labarre, J. and Toledano, M.B. ATP-dependent reduction of cysteine-sulphinic acid by S. cerevisiae sulphiredoxin. Nature 425 (2003) 980-984. [PMID: 14586471]

2. Chang, T.S., Jeong, W., Woo, H.A., Lee, S.M., Park, S. and Rhee, S.G. Characterization of mammalian sulfiredoxin and its reactivation of hyperoxidized peroxiredoxin through reduction of cysteine sulfinic acid in the active site to cysteine. J. Biol. Chem. 279 (2004) 50994-51001. [PMID: 15448164]

3. Woo, H.A., Jeong, W., Chang, T.S., Park, K.J., Park, S.J., Yang, J.S. and Rhee, S.G. Reduction of cysteine sulfinic acid by sulfiredoxin is specific to 2-Cys peroxiredoxins. J. Biol. Chem. 280 (2005) 3125-3128. [PMID: 15590625]

[EC created 2005]

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