EC - Acetylenecarboxylate hydratase

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IntEnz Enzyme Nomenclature


Accepted name:
acetylenecarboxylate hydratase
Other names:
acetylenemonocarboxylate hydrase
acetylenemonocarboxylate hydratase
acetylmonocarboxylic acid hydrase
alkynoate hydratase
malonate-semialdehyde dehydratase
3-oxopropanoate hydro-lyase
Systematic name:
3-oxopropanoate hydro-lyase (propynoate-forming)



The reaction is effectively irreversible, favouring oxopropanoate (malonic semialdehyde) and its tautomers. Also acts on 3-butynoate forming acetoacetate. The mechanism appears to involve hydration of the acetylene to 3-hydroxypropenoate, which will spontaneously tautomerize to 3-oxopropanoate. It is thus analogous to EC, acetylenedicarboxylate decarboxylase, in its mechanism.

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0051909 , GO:0050079
CAS Registry Number: 9024-26-4


  1. Van den Tweel, W.J.J. and De Bont, J.A.M.
    Metabolism of 3-butyn-1-ol by Pseudomonas BB1.
    J. Gen. Microbiol. 131: 3155-3162 (1985). [PMID: 16525953]
  2. Yamada, E.W. and Jakoby, W.B.
    Enzymatic utilization of acetylenic compounds. II. Acetylenemonocarboxylic acid hydrase.
    J. Biol. Chem. 234: 941-945 (1959). [PMID: 13654296]

[EC created 1965, (EC created 1978, modified 1989, modified 2000, incorporated 2004) modified 2004]