S-adenosylmethionine decarboxylase (AdoMetDC) isolated from Thermotoga maritima is an enzyme that catalyses the decarboxylation of S-adenosylmethionine (AdoMet or SAM) to S-adenosyl-5'-(3-methylthiopropylamine) (dcAdoMet). AdoMetDC is regulatory enzyme in the biosynthesis of spermine and spermidine. It is a class 1B AdoMetDC and belongs to a small family of decarboxylating enzymes that act on amino acids using bound pyruvate as an electron sink. AdoMetDC is synthesised as a proenzyme and must undergo self-maturation by nonhydrolytic serinolysis. It is during this process that the pyruvate group is formed at the carboxy terminus of the alpha chain.
Defined by 5 residues: GLU:A-74 [auth A-62]SER:A-75 [auth A-63]CYS:A-95 [auth A-83]SER:B-67 [auth B-55]HIS:B-80 [auth B-68]