IntEnz

EC 1.11.1.15 - Peroxiredoxin

IntEnz Enzyme Nomenclature
EC 1.11.1.15

Names

Reaction

• 10008 [IUBMB]
  [protein]-dithiol

  [protein]-dithiol

  GENERIC:10594

  Is ROOT: no
  ROOT compound: GENERIC:9624

  Number of residues: 2

  L-cysteine residue L-cysteine residue Name origin: UniProt - CHECKED (C) CHEBI:29950 Formula: C3H5NOS Charge: 0 Position: C1 ChEBI compound status: CHECKED (C)

  L-cysteine residue L-cysteine residue Name origin: UniProt - CHECKED (C) CHEBI:29950 Formula: C3H5NOS Charge: 0 Position: C2 ChEBI compound status: CHECKED (C)

  +

  an hydroperoxide

  an hydroperoxide

  Name origin: UniProt - CHECKED (C)

  CHEBI:35924

  Formula: HO2R
  Charge: 0

  ChEBI compound status: CHECKED (C)

  

  =

  [protein]-disulfide

  [protein]-disulfide

  GENERIC:10593

  Is ROOT: no
  ROOT compound: GENERIC:9624

  Number of residues: 1

  L-cystine residue L-cystine residue Name origin: UniProt - CHECKED (C) CHEBI:50058 Formula: C6H8N2O2S2 Charge: 0 Position: undefined ChEBI compound status: CHECKED (C)

  +

  an alcohol

  an alcohol

  Name origin: UniProt - CHECKED (C)

  CHEBI:30879

  Formula: HOR
  Charge: 0

  ChEBI compound status: CHECKED (C)

  

  +

  H₂O

  H2O

  Name origin: UniProt - CHECKED (C)

  CHEBI:15377

  Formula: H2O
  Charge: 0

  ChEBI compound status: CHECKED (C)

  

Comments:

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 [1]. 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). 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 (R'-SH) (e.g. thioredoxin, AhpF, tryparedoxin or AhpD), 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 [1]. To recycle the disulfide, known atypical 2-Cys Prxs appear to use thioredoxin as an electron donor [3]. The 1-Cys Prxs conserve only the peroxidatic cysteine, so that its oxidized form is directly reduced to cysteine by the reductant molecule [4].

Links to other databases

References

1. Wood, Z.A., Schröder, E., Harris, J.R. and Poole, L.B.
   Structure, mechanism and regulation of peroxiredoxins.
   Trends Biochem. Sci. 28: 32-40 (2003).
2. Hofmann, B., Hecht, H J. and Flohé, L.
   Peroxiredoxins.
   Biol. Chem. 383: 347-364 (2002). [PMID: 12033427]
3. Seo, M.S., Kang, S.W., Kim, K., Baines, I.C., Lee, T.H. and Rhee, S.G.
   Identification of a new type of mammalian peroxiredoxin that forms an intramolecular disulfide as a reaction intermediate.
   J. Biol. Chem. 275: 20346-20354 (2000). [PMID: 10751410]
4. Choi, H.J., Kang, S.W., Yang, C.H., Rhee, S.G. and Ryu, S.E.
   Crystal structure of a novel human peroxidase enzyme at 2.0 Å resolution.
   Nat. Struct. Biol. 5: 400-406 (1998). [PMID: 9587003]

[EC 1.11.1.15 created 2004]