| Type: | Conserved_site | Name: | Polyamine biosynthesis domain, conserved site |
| Description: | The nearly ubiquitous polyamines (putrescine, spermidine and spermine) are polycationic mediators of cell proliferation and differentiation whosefunctions likely provide both stability and neutralisation for nucleic acids. The following polyamine biosynthetic enzymes are evolutionary related andcontain a polyamine biosynthesis (PABS) domain []:Spermidine synthase () (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 () (spermidine aminopropyltransferase). It converts spermidine into spermine using decarboxylated S-adenosylmethionine as the cofactor.Putrescine N-methyltransferase (). 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. | Short Name: | PABS_CS |
