In enzymology, a tRNA-uridine aminocarboxypropyltransferase () is an enzyme that catalyzes the chemical reaction S-adenosyl-L-methionine + tRNA uridine 5'-methylthioadenosine + tRNA 3-(3-amino-3-carboxypropyl)-uridine Thus, the two substrates of this enzyme are S-adenosyl-L-methionine and tRNA uridine, whereas its two products are 5'-methylthioadenosine and tRNA 3-(3-amino-3-carboxypropyl)-uridine. This enzyme belongs to the family of transferases, specifically those transferring aryl or alkyl groups other than methyl groups. The systematic name of this enzyme class is S-adenosyl-L-methionine:tRNA-uridine 3-(3-amino-3-carboxypropyl)transferase. References EC 2.5.1 Enzymes of unknown structure