Reaction: S-adenosyl 3-(methylsulfanyl)propylamine + norspermine = S-methyl-5'-thioadenosine + caldopentamine
Glossary: caldopentamine = N-(3-aminopropyl)-N'-{3-[(3-aminopropyl)amino]propyl}-1,3-propanediamine
norspermidine = N-(3-aminopropyl)-1,4-butanediamine
norspermine = N,N'-bis(3-aminopropyl)-1,3-propanediamine
spermidine = N-(3-aminopropyl)-1,4-butanediamine
thermospermine = N-{3-[(3-aminopropyl)amino]propyl}-1,4-butanediamine
Other name(s): long-chain polyamine synthase (ambiguous); S-adenosyl 3-(methylthio)propylamine:norspermine 3-aminopropyltransferase
Systematic name: S-adenosyl 3-(methylsulfanyl)propylamine:norspermine 3-aminopropyltransferase
Comments: 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.
Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number:
References:
1. Knott, J.M. Biosynthesis of long-chain polyamines by crenarchaeal polyamine synthases from Hyperthermus butylicus and Pyrobaculum aerophilum. FEBS Lett 583 (2009) 3519-3524. [PMID: 19822146]