IUBMB Enzyme Nomenclature


Accepted name: 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase

Reaction: 5-enolpyruvoyl-6-hydroxy-2-succinylcyclohex-3-ene-1-carboxylate = (1R,6R)-6-hydroxy-2-succinylcyclohexa-2,4-diene-1-carboxylate + pyruvate

For diagram of reaction, click here.

Other name(s): 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylic acid synthase; 6-hydroxy-2-succinylcyclohexa-2,4-diene-1-carboxylate synthase; SHCHC synthase; MenH; YfbB

Systematic name: 5-enolpyruvoyl-6-hydroxy-2-succinylcyclohex-3-ene-1-carboxylate pyruvate-lyase [(1R,6R)-6-hydroxy-2-succinylcyclohexa-2,4-diene-1-carboxylate-forming)

Comments: This enzyme is involved in the biosynthesis of vitamin K2 (menaquinone). In most anaerobes and all Gram-positive aerobes, menaquinone is the sole electron transporter in the respiratory chain and is essential for their survival. It had previously been thought that the reactions carried out by this enzyme and EC, 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylic-acid synthase, were carried out by a single enzyme but this has since been disproved [2].

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 122007-88-9


1. Jiang, M., Chen, X., Guo, Z.F., Cao, Y., Chen, M. and Guo, Z. Identification and characterization of (1R,6R)-2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase in the menaquinone biosynthesis of Escherichia coli. Biochemistry 47 (2008) 3426-3434. [PMID: 18284213]

2. Jiang, M., Cao, Y., Guo, Z.F., Chen, M., Chen, X. and Guo, Z. Menaquinone biosynthesis in Escherichia coli: identification of 2-succinyl-5-enolpyruvyl-6-hydroxy-3-cyclohexene-1-carboxylate as a novel intermediate and re-evaluation of MenD activity. Biochemistry 46 (2007) 10979-10989. [PMID: 17760421]

[EC created 2008 (EC created 2003, part-incorporated 2008)]

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