EC - 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase

  IntEnz view ENZYME view

IntEnz Enzyme Nomenclature


Accepted name:
2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase
Other names:
OHCU decarboxylase
hpxQ (gene name)
PRHOXNB (gene name)
Systematic name:
5-hydroxy-2-oxo-4-ureido-2,5-dihydro-1H-imidazole-5-carboxylate carboxy-lyase [S-allantoin-forming]



This enzyme is part of the pathway from urate to (S)-allantoin, which is present in bacteria, plants and animals (but not in humans). Formerly EC 4.1.1.n1.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
UniProtKB/Swiss-Prot: (13) [show] [UniProt]


  1. Ramazzina, I., Folli, C., Secchi, A., Berni, R., Percudani, R.
    Completing the uric acid degradation pathway through phylogenetic comparison of whole genomes.
    Nat. Chem. Biol. 2 : 144-148 (2006). [PMID: 16462750]
  2. Cendron, L., Berni, R., Folli, C., Ramazzina, I., Percudani, R., Zanotti, G.
    The structure of 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase provides insights into the mechanism of uric acid degradation.
    J. Biol. Chem. 282 : 18182-18189 (2007). [PMID: 17428786]
  3. Kim, K., Park, J., Rhee, S.
    Structural and functional basis for (S)-allantoin formation in the ureide pathway.
    J. Biol. Chem. 282 : 23457-23464 (2007). [PMID: 17567580]
  4. French, J. B., Ealick, S. E.
    Structural and mechanistic studies on Klebsiella pneumoniae 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline decarboxylase.
    J. Biol. Chem. 285 : 35446-35454 (2010). [PMID: 20826786]

[EC created 2014]