InterPro domain: IPR016067

S-adenosylmethionine decarboxylase (AdoMetDC) [ 1 ] catalyzes the removal of the carboxylate group of S-adenosylmethionine to form S-adenosyl-5'-3-methylpropylamine which then acts as the n-propylamine group donor in the synthesis of the polyamines spermidine and spermine from putrescine.

The catalytic mechanism of AdoMetDC involves a covalently-bound pyruvoyl group. This group is post-translationally generated by a self-catalyzed intramolecular proteolytic cleavage reaction between a glutamate and a serine. This cleavage generates two chains, beta (N-terminal) and alpha (C-terminal). The N-terminal serine residue of the alpha chain is then converted by nonhydrolytic serinolysis into a pyruvyol group.

1. The crystal structure of human S-adenosylmethionine decarboxylase at 2.25 A resolution reveals a novel fold. Structure 7, 583-95