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EC 1.8.98.2 Details
show Brenda entryEC number
1.8.98.2
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]
CAS registry number
710319-61-2
Comment
In the course of the reaction of EC 1.11.1.15, 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.
History
created 2005
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1 Oxidoreductases
1.1.1 With NAD+ or NADP+ as acceptor
1.1.3.1 created 1961, deleted 1984 1.1.3.25 created 1986, deleted 2005 1.1.3.26 created 1989, deleted 2002 1.1.3.31 created 1992, deleted 2003 1.1.3.32 created 1999, deleted 2002 1.1.3.33 created 1999, deleted 2002 1.1.3.34 created 1999, deleted 2002 1.1.3.35 created 1999, deleted 2002 1.1.3.36 created 1999, deleted 2002
