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 [, ]. 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 []. Elevated levels of QUIN have been observed in several neuropsychiatric and neurodegenerative conditions [, , ].The entry also includes decarboxylases OrsB, MacB 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 []. 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 [].
