IUBMB Enzyme Nomenclature


Accepted name: thermospermine synthase

Reaction: S-adenosyl 3-(methylsulfanyl)propylamine + spermidine = S-methyl-5'-thioadenosine + thermospermine + H+

Glossary: thermospermine = N1-[3-(3-aminopropylamino)propyl]butane-1,4-diamine
S-adenosyl 3-(methylsulfanyl)propylamine = (3-aminopropyl){[(2S,3S,4R,5R)-5-(6-amino-9H-purin-9-yl)-3,4-dihydroxytetrahydrofuran-2-yl]methyl}methylsulfonium

Other name(s): TSPMS; ACL5; SAC51; S-adenosyl 3-(methylthio)propylamine:spermidine 3-aminopropyltransferase (thermospermine synthesizing)

Systematic name: S-adenosyl 3-(methylsulfanyl)propylamine:spermidine 3-aminopropyltransferase (thermospermine forming)

Comments: This enzyme is crucial for the proper functioning of xylem vessel elements in the vascular tissues of plants [3].

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


1. Romer, P., Faltermeier, A., Mertins, V., Gedrange, T., Mai, R. and Proff, P. Investigations about N-aminopropyl transferases probably involved in biomineralization. J. Physiol. Pharmacol. 59 Suppl 5 (2008) 27-37. [PMID: 19075322]

2. Knott, J.M., Romer, P. and Sumper, M. Putative spermine synthases from Thalassiosira pseudonana and Arabidopsis thaliana synthesize thermospermine rather than spermine. FEBS Lett. 581 (2007) 3081-3086. [PMID: 17560575]

3. Muniz, L., Minguet, E.G., Singh, S.K., Pesquet, E., Vera-Sirera, F., Moreau-Courtois, C.L., Carbonell, J., Blazquez, M.A. and Tuominen, H. ACAULIS5 controls Arabidopsis xylem specification through the prevention of premature cell death. Development 135 (2008) 2573-2582. [PMID: 18599510]

[EC created 2010, modified 2013]

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