IUBMB Enzyme Nomenclature


Accepted name: norspermine synthase

Reaction: S-adenosyl 3-(methylsulfanyl)propylamine + norspermidine = S-methyl-5'-thioadenosine + norspermine

Glossary: norspermidine = bis(3-aminopropyl)amine
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:norspermidine 3-aminopropyltransferase

Systematic name: S-adenosyl 3-(methylsulfanyl)propylamine:norspermidine 3-aminopropyltransferase

Comments: The enzyme, characterized from the thermophilic archaeon Pyrobaculum aerophilum, can also synthesize norspermidine from propane-1,3-diamine and thermospermine from spermidine (with lower activity). The long-chain polyamines stabilize double-stranded DNA at high temperatures. In contrast to EC, caldopentamine synthase, this enzyme does not accept norspermine as a substrate.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


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]

[EC created 2014]

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