ENZYME entry: EC 126.96.36.199
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|[mycoredoxin]-L-dithiol + a hydroperoxide <=> [mycoredoxin]-L-disulfide + an alcohol + H2O|
- Peroxiredoxins (Prxs) are a ubiquitous family of antioxidant
- They can be divided into three classes: typical 2-Cys, atypical 2-Cys
and 1-Cys peroxiredoxins.
- The peroxidase reaction comprises two steps centered 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).
- The second step of the peroxidase reaction, the regeneration of
cysteine from S-hydroxycysteine, distinguishes the three
- 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
- 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.
- The 1-Cys Prxs conserve only the peroxidatic cysteine, so its
regeneration involves direct interaction with a reductant molecule.
- Mycoredoxin-dependent enzymes are found in Mycobacteria.
- Following the reduction of the substrate, the sulfenic acid
derivative of the peroxidatic cysteine forms a protein mixed
disulfide with the N-terminal cysteine of mycoredoxin, which is then
reduced by the C-terminal cysteine of mycoredoxin, restoring the
peroxiredoxin to active state and resulting in an intra-protein
disulfide in mycoredoxin.
- The disulfide is eventually reduced by mycothiol.
- Formerly EC 188.8.131.52.
|PRIAM enzyme-specific profiles||184.108.40.206|
|KEGG Ligand Database for Enzyme Nomenclature||220.127.116.11|
|IUBMB Enzyme Nomenclature||18.104.22.168|
|MEDLINE||Find literature relating to 22.214.171.124|
|Rhea expert-curated reactions||126.96.36.199|
entries corresponding to 1.11.1.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.11.-.-
All ENZYME / UniProtKB/Swiss-Prot entries corresponding to 1.-.-.-