IUBMB Enzyme Nomenclature


Accepted name: 4-hydroxy-2-oxoheptanedioate aldolase

Reaction: 4-hydroxy-2-oxoheptanedioate = pyruvate + succinate semialdehyde

Other name(s): 2,4-dihydroxyhept-2-enedioate aldolase; HHED aldolase; 4-hydroxy-2-ketoheptanedioate aldolase; HKHD aldolase; HpcH; HpaI; 4-hydroxy-2-oxoheptanedioate succinate semialdehyde lyase (pyruvate-forming)

Systematic name: 4-hydroxy-2-oxoheptanedioate succinate-semialdehyde-lyase (pyruvate-forming)

Comments: Requires Co2+ or Mn2+ for activity. The enzyme is also able to catalyse the aldol cleavage of 4-hydroxy-2-oxopentanoate and 4-hydroxy-2-oxohexanoate, and can use 2-oxobutanoate as carbonyl donor, with lower efficiency. In the reverse direction, is able to condense a range of aldehyde acceptors with pyruvate. The enzyme from the bacterium Escherichia coli produces a racemic mixture of (4R)- and (4S)-hydroxy-2-oxoheptanedioate [4].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Wang, W. and Seah, S.Y. Purification and biochemical characterization of a pyruvate-specific class II aldolase, HpaI. Biochemistry 44 (2005) 9447-9455. [PMID: 15996099]

2. Rea, D., Fulop, V., Bugg, T.D. and Roper, D.I. Structure and mechanism of HpcH: a metal ion dependent class II aldolase from the homoprotocatechuate degradation pathway of Escherichia coli. J. Mol. Biol. 373 (2007) 866-876. [PMID: 17881002]

3. Wang, W. and Seah, S.Y. The role of a conserved histidine residue in a pyruvate-specific class II aldolase. FEBS Lett 582 (2008) 3385-3388. [PMID: 18775708]

4. Wang, W., Baker, P. and Seah, S.Y.K. Comparison of two metal-dependent pyruvate aldolases related by convergent evolution: substrate specificity, kinetic mechanism, and substrate channeling. Biochemistry 49 (2010) 3774-3782. [PMID: 20364820]

[EC created 2013]

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