Also known as SPED_GEOTN, speD. Catalyzes the decarboxylation of S-adenosylmethionine to S-adenosylmethioninamine (dcAdoMet), the propylamine donor required for the synthesis of the polyamines spermine and spermidine from the diamine putrescine. Heterooctamer of four alpha and four beta chains arranged as a tetramer of alpha/beta heterodimers.
