IUBMB Enzyme Nomenclature


Accepted name: 2-hydroxymuconate-6-semialdehyde dehydrogenase

Reaction: 2-hydroxymuconate-6-semialdehyde + NAD+ + H2O = (2Z,4E)-2-hydroxyhexa-2,4-dienedioate + NADH + 2 H+

For diagram of reaction click here.

Glossary: 2-hydroxymuconate-6-semialdehyde = (2Z,4E)-2-hydroxy-6-oxohexa-2,4-dienoate

Other name(s): xylG (gene name); praB (gene name)

Systematic name: 2-hydroxymuconate-6-semialdehyde:NAD+ oxidoreductase

Comments: This substrate for this enzyme is formed by meta ring cleavage of catechol (EC, catechol 2,3-dioxygenase), and is an intermediate in the bacterial degradation of several aromatic compounds. Has lower activity with benzaldehyde [1]. Activity with NAD+ is more than 10-fold higher than with NADP+ [3]. cf. EC, aminomuconate-semialdehyde dehydrogenase.

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


1. Inoue, J., Shaw, J.P., Rekik, M. and Harayama, S. Overlapping substrate specificities of benzaldehyde dehydrogenase (the xylC gene product) and 2-hydroxymuconic semialdehyde dehydrogenase (the xylG gene product) encoded by TOL plasmid pWW0 of Pseudomonas putida. J. Bacteriol. 177 (1995) 1196-1201. [PMID: 7868591]

2. Orii, C., Takenaka, S., Murakami, S. and Aoki, K. Metabolism of 4-amino-3-hydroxybenzoic acid by Bordetella sp. strain 10d: A different modified meta-cleavage pathway for 2-aminophenols. Biosci. Biotechnol. Biochem. 70 (2006) 2653-2661. [PMID: 17090920]

3. Kasai, D., Fujinami, T., Abe, T., Mase, K., Katayama, Y., Fukuda, M. and Masai, E. Uncovering the protocatechuate 2,3-cleavage pathway genes. J. Bacteriol. 191 (2009) 6758-6768. [PMID: 19717587]

[EC created 2012]

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