EC - 2-oxopent-4-enoate hydratase

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IntEnz Enzyme Nomenclature


Accepted name:
2-oxopent-4-enoate hydratase
Other names:
2-keto-4-pentenoate hydratase
2-keto-4-pentenoate (vinylpyruvate)hydratase
4-hydroxy-2-oxopentanoate hydro-lyase
mhpD (gene name)
4-hydroxy-2-oxopentanoate hydro-lyase (2-oxopent-4-enoate-forming)
ahdF (gene name)
todG (gene name)
cmtF (gene name)
xylJ (gene name)
cnbE (gene name)
Systematic name:
(S)-4-hydroxy-2-oxopentanoate hydro-lyase ((2Z)-2-hydroxypenta-2,4-dienoate-forming)



The enzyme is involved in the catechol meta-cleavage pathway, a major mechanism for degradation of aromatic compounds. Also acts, more slowly, on cis-2-oxohex-4-enoate, but not on the trans-isomer. The enzyme was named when it was thought that the substrate is 2-oxopent-4-enoate. However, it was later found that the actual substrate is its tautomer (2Z)-2-hydroxypenta-2,4-dienoate. In some organisms the enzyme forms a complex with EC, 2-oxo-3-hexenedioate decarboxylase (previously named 4-oxalocrotonate decarboxylase).

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , DIAGRAM , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UM-BBD , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0008684
CAS Registry Numbers: 227181-25-1 229017-66-7 64427-80-1
UniProtKB/Swiss-Prot: (24) [show] [UniProt]


  1. Kunz, D.A., Ribbons, D.W. and Chapman, P.J.
    Metabolism of allylglycine and cis-crotylglycine by Pseudomonas putida (arvilla) mt-2 harboring a TOL plasmid.
    J. Bacteriol. 148 : 72-82 (1981). [PMID: 7287632]
  2. Harayama, S., Rekik, M., Ngai, K. L., Ornston, L. N.
    Physically associated enzymes produce and metabolize 2-hydroxy-2,4-dienoate, a chemically unstable intermediate formed in catechol metabolism via meta cleavage in Pseudomonas putida.
    J. Bacteriol. 171 : 6251-6258 (1989). [PMID: 2681159]
  3. Pollard, J. R., Bugg, T. D.
    Purification, characterisation and reaction mechanism of monofunctional 2-hydroxypentadienoic acid hydratase from Escherichia coli.
    Eur. J. Biochem. 251 : 98-106 (1998). [PMID: 9492273]

[EC created 1984]