IUBMB Enzyme Nomenclature


Accepted name: 2-hydroxychromene-2-carboxylate isomerase

Reaction: 2-hydroxy-2H-chromene-2-carboxylate = (3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate

For diagram of reaction, click here

Other name(s): HCCA isomerase; 2HC2CA isomerase; 2-hydroxychromene-2-carboxylic acid isomerase

Systematic name: 2-hydroxy-2H-chromene-2-carboxylate—(3E)-4-(2-hydroxyphenyl)-2-oxobut-3-enoate isomerase

Comments: This enzyme is involved in naphthalene degradation.

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


1. Ohmoto, T., Kinoshita, T., Moriyoshi, K., Sakai, K., Hamada, N. and Ohe, T. Purification and some properties of 2-hydroxychromene-2-carboxylate isomerase from naphthalenesulfonate-assimilating Pseudomonas sp. TA-2. J. Biochem. 124 (1998) 591-597. [PMID: 9722670]

2. Keck, A., Conradt, D., Mahler, A., Stolz, A., Mattes, R. and Klein, J. Identification and functional analysis of the genes for naphthalenesulfonate catabolism by Sphingomonas xenophaga BN6. Microbiology 152 (2006) 1929-1940. [PMID: 16804169]

3. Eaton, R.W. Organization and evolution of naphthalene catabolic pathways: sequence of the DNA encoding 2-hydroxychromene-2-carboxylate isomerase and trans-o-hydroxybenzylidenepyruvate hydratase-aldolase from the NAH7 plasmid. J. Bacteriol. 176 (1994) 7757-7762. [PMID: 8002605]

4. Thompson, L.C., Ladner, J.E., Codreanu, S.G., Harp, J., Gilliland, G.L. and Armstrong, R.N. 2-Hydroxychromene-2-carboxylic acid isomerase: a kappa class glutathione transferase from Pseudomonas putida. Biochemistry 46 (2007) 6710-6722. [PMID: 17508726]

[EC created 2010]

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