Conserved Site

Polyamine biosynthesis domain, conserved site (IPR030373)

Short name: PABS_CS


The nearly ubiquitous polyamines (putrescine, spermidine and spermine) are polycationic mediators of cell proliferation and differentiation whose functions likely provide both stability and neutralisation for nucleic acids. The following polyamine biosynthetic enzymes are evolutionary related and contain a polyamine biosynthesis (PABS) domain [PMID: 9517003]:

  • Spermidine synthase (EC: (putrescine aminopropyltransferase). It catalyses the last step in the biosynthesis of spermidine from arginine and methionine; the conversion of putrescine to spermidine using decarboxylated S-adenosylmethionine as the cofactor.
  • Spermine synthase (EC: (spermidine aminopropyltransferase). It converts spermidine into spermine using decarboxylated S-adenosylmethionine as the cofactor.
  • Putrescine N-methyltransferase (EC: It catalyses a step in the biosynthesis of nicotine in plants; the methylation of putrescine to N-methylputrescine using S-adenosylmethionine as the cofactor.

This conserved site consists of a glycine-rich conserved region in the PABS domain.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns