Isonocardicin synthase () is an enzyme that catalyzes a chemical reaction which transfers the 3-amino-3-carboxypropyl group from its coenzyme, S-adenosyl methionine (SAM), giving 5'-methylthioadenosine as a byproduct. The enzyme from Nocardia uniformis can act on several natural beta lactams of the nocardicin type but the main reaction in the biosynthetic pathway leading to nocardicin A converts nocardicin G to isonocardicin C:
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:nocardicin-E 3-amino-3-carboxypropyltransferase. This enzyme is also called nocardicin aminocarboxypropyltransferase.
References