Spermine synthase is an enzyme involved in polyamine biosynthesis. It is present in all eukaryotes and plays a role in a variety of biological functions in plants[3] Its structure consists of two identical monomers of 41 kDa with three domains each, creating a homodimer formed via dimerization. The interactions between one of the three domains, the N-terminals of the monomers, is responsible for dimerization as that is where the active site is located; the central terminal consisting of four β- strands structurally forming a lid for the third domain, the C-terminal domain.[4]
^Imamura T, Fujita K, Tasaki K, Higuchi A, Takahashi H (August 2015). "Characterization of spermidine synthase and spermine synthase--The polyamine-synthetic enzymes that induce early flowering in Gentiana triflora". Biochemical and Biophysical Research Communications. 463 (4): 781–6. doi:10.1016/j.bbrc.2015.06.013. PMID26056006.
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