ADP-Ribosyltransferase, NAD

An enzyme that catalyze the Transfer of ADP-Ribose from NAD+ to an amino acid residue in a specific protein substrate. This reaction is catalyzed by both Mono(ADP-Ribose) Transferases as well as Poly(ADP-ribose) Polymerases. When the term NAD+ ADP-Ribosyltransferase refers to EC it is referring to Poly(ADP-ribose) Polymerases.