Spermidine Synthase (SRM)

The biosynthesis of polyamines, which are universally essential for cellular functions, takes place from arginine and methionine and involves 4 distinct enzymes: spermidine synthase (EC 2.5.1.16), ornithine decarboxylase , S-adenosyl-L-methionine decarboxylase, and spermine synthase. An open reading frame for a 302-amino acid polypeptide was found. As determined from the intensity of the hybridization signal observed in analysis of DNA from somatic cell hybrids, it seemed likely that the functional gene is located at the former site. it comprises 5,818 nucleotides from the cap site to the last A of the putative polyadenylation signal with 8 exons and 7 intervening sequences. PCR analysis of DNA obtained from human/hamster somatic cell hybrids showed segregation with human chromosome 1.