Reaction: 4-carboxy-2-hydroxymuconate semialdehyde hemiacetal + NADP+ = 2-oxo-2H-pyran-4,6-dicarboxylate + NADPH + H+
For diagram of reaction click here
Other name(s): 2-hydroxy-4-carboxymuconate 6-semialdehyde dehydrogenase; 4-carboxy-2-hydroxy-cis,cis-muconate-6-semialdehyde:NADP+ oxidoreductase; α-hydroxy-γ-carboxymuconic ε-semialdehyde dehydrogenase; 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase; LigC; ProD
Systematic name: 4-carboxy-2-hydroxymuconate semialdehyde hemiacetal:NADP+ 2-oxidoreductase
Comments: The enzyme does not act on unsubstituted aliphatic or aromatic aldehydes or glucose; NAD+ can replace NADP+, but with lower affinity. The enzyme was initially believed to act on 4-carboxy-2-hydroxy-cis,cis-muconate 6-semialdehyde and produce 4-carboxy-2-hydroxy-cis,cis-muconate [1]. However, later studies showed that the substrate is the hemiacetal form [3], and the product is 2-oxo-2H-pyran-4,6-dicarboxylate [2,4].
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 67272-39-3
References:
1. Maruyama, K., Ariga, N., Tsuda, M. and Deguchi, K. Purification and properties of α-hydroxy-γ-carboxymuconic ε-semialdehyde dehydrogenase. J. Biochem. (Tokyo) 83 (1978) 1125-1134. [PMID: 26671]
2. Maruyama, K. Isolation and identification of the reaction product of α-hydroxy-γ-carboxymuconic ε-semialdehyde dehydrogenase. J. Biochem. 86 (1979) 1671-1677. [PMID: 528534]
3. Maruyama, K. Purification and properties of 2-pyrone-4,6-dicarboxylate hydrolase. J. Biochem. (Tokyo) 93 (1983) 557-565. [PMID: 6841353]
4. Masai, E., Momose, K., Hara, H., Nishikawa, S., Katayama, Y. and Fukuda, M. Genetic and biochemical characterization of 4-carboxy-2-hydroxymuconate-6-semialdehyde dehydrogenase and its role in the protocatechuate 4,5-cleavage pathway in Sphingomonas paucimobilis SYK-6. J. Bacteriol. 182 (2000) 6651-6658. [PMID: 11073908]