S-Adenosylmethionine decarboxylase belongs to a small class of amino acid decarboxylases that use a covalently bound pyruvate as a prosthetic group. It is an essential enzyme for polyamine biosynthesis and provides an important target for the design of anti-parasitic and cancer chemotherapeutic agents. It catalyzes the formation of the aminopropyl group donor in the biosynthesis of the polyamines spermidine and spermine. These pyruvoyl-dependent decarboxylases also form amines such as histamine, decarboxylated S-adenosylmethionine, phosphatidylethanolamine (a component of membrane phospholipids), and -alanine (a precursor of coenzyme A), which are all of critical importance in cellular physiology and provide important targets for drug design.