InterPro domain: IPR032465

2-amino-3-carboxymuconate-6-semialdehyde decarboxylase, also known as picolinate carboxylase or ACMSD, is a member of the amidohydrolase superfamily involved in tryptophan metabolism [ 1 , 2 ]. It converts alpha-amino-beta-carboxymuconate-epsilon-semialdehyde (ACMS) to alpha-aminomuconate semialdehyde (AMS). ACMSD has medical importance as its substrate ACMS is unstable and dehydrates to quinolinic acid (QUIN, QA), not only a key precursor of NAD, but also a potent neurotoxin [ 3 ]. Elevated levels of QUIN have been observed in several neuropsychiatric and neurodegenerative conditions [ 4 , 5 , 6 ].

The entry also includes decarboxylases OrsB and YanB, and salicylate decarboxylase.

YanB is a decarboxylase and part of the gene cluster that mediates the biosynthesis of yanuthone D, a fungal isoprenoid epoxycyclohexenone that acts as an antibiotic against fungi and bacteria [ 7 ]. Salicylate decarboxylase has been shown to catalyse both the decarboxylation of salicylic acid to produce phenol, and the carboxylation of phenol to form salicylic acid [ 8 ].

1. Alpha-amino-beta-carboxymuconic-epsilon-semialdehyde decarboxylase (ACMSD) is a new member of the amidohydrolase superfamily. Biochemistry 45, 6628-34
2. Tissue expression and biochemical characterization of human 2-amino 3-carboxymuconate 6-semialdehyde decarboxylase, a key enzyme in tryptophan catabolism. FEBS J. 274, 827-40
3. The crystal structure of human alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase in complex with 1,3-dihydroxyacetonephosphate suggests a regulatory link between NAD synthesis and glycolysis. FEBS J. 276, 6615-23
4. Tryptophan metabolites and brain disorders. Clin. Chem. Lab. Med. 41, 852-9
5. Quinolinic acid in the pathogenesis of Alzheimer's disease. Adv. Exp. Med. Biol. 527, 167-76
6. 3-Hydroxykynurenine and quinolinate: pathogenic synergism in early grade Huntington's disease? Adv. Exp. Med. Biol. 527, 137-45
7. Molecular and chemical characterization of the biosynthesis of the 6-MSA-derived meroterpenoid yanuthone D in Aspergillus niger. Chem. Biol. 21, 519-29
8. Enzymatic Kolbe-Schmitt reaction to form salicylic acid from phenol: enzymatic characterization and gene identification of a novel enzyme, Trichosporon moniliiforme salicylic acid decarboxylase. Biochem. Biophys. Res. Commun. 394, 279-84