Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

Official Name

spermidine synthase

Name from literature

spermidine synthase

Pathway from literature

formation of the spermine precursor spermidine from putrescine

Pathway from KEGG

Metabolism of Other Amino Acids; Glutathione metabolism; map00480

Amino Acid Metabolism; Urea cycle and metabolism of amino groups; map00220

Metabolism of Other Amino Acids; beta-Alanine metabolism; map00410

Amino Acid Metabolism; Methionine metabolism; map00271


Human (9606)

Genome localization

1p36-p22[6723 ],


This enzyme is not identical with EC, spermine synthase. The mammalian enzyme is highly specific but the bacterial enzyme can use other acceptors and can synthesize spermine.

Rate-limiting Description

"The rate-limiting enzymes in polyamine biosynthesis, ornithine decarboxylase (ODC) and S-adenosylmethionine decarboxylase (AdoMetDC), are negatively regulated by the polyamines spermidine and spermine." (2775206)

Regulatory Information

Upstream transcription factor


Regulatory type



"Spermidine synthase (SPDS) catalyzes transfer of the propylamine group from decarboxylated S-adenosylmethionine (dcSAM) to putrescine to yield methylthioadenosine (MTA) and spermidine. SPDS plays a regulatory role in cell proliferation and differentiation." (16472757)


"The results show that the GC-rich 5'-untranslated region of spermidine synthase mRNA has an inhibitory effect on its translation." (7774716)

transcriptional factor;REST(5978)

"This sequence census method was then used to map in vivo binding of the neuron-restrictive silencer factor (NRSF; also known as REST, for repressor element-1 silencing transcription factor) to 1946 locations in the human genome." (17540862)

Gene ontology

Gene ontology

GO:0008295 (P) spermidine biosynthetic process [P19623 ];
GO:0004766 (F) spermidine synthase activity [P19623 ];




Entrez Gene




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  Last Modified: 2009-03-24  
  Design by Zhao Min