Description
The enzyme, characterized from the thermophilic archaeon Hyperthermus butylicus, can also synthesize norspermine from norspermidine and thermospermine from spermidine (with lower activity). The long-chain polyamines stabilize double-stranded DNA at high temperatures. In contrast to EC 2.5.1.23, sym-norspermidine synthase and EC 2.5.1.126, norspermine synthase, this enzyme shows no activity with propane-1,3-diamine