Spermine Synthase (SMS)

Spermine synthase (EC 2.5.1.22) is 1 of 4 enzymes involved in the synthesis of polyamines from arginine and methionine. The others are ornithine decarboxylase, S-adenosyl-L-methionine decarboxylase , and spermidine synthase.Korhonen et al. (1995) isolated and sequenced cDNA clones encoding human spermine synthase.

The open reading frame encodes a 368-amino acid protein with little sequence similarity to proteins from bacterial and mammalian sources catalyzing almost identical reactions.In affected members of a family with Snyder-Robinson mental retardation syndrome (SRS) originally reported by Snyder and Robinson (1969), Cason et al. (2003) identified a splice site mutation in the SMS gene .