NAD+ nucleosidase activity, cyclic ADP-ribose generating
nad+ nucleosidase activity, cyclic adp-ribose generating
Catalysis of the reaction: NAD+ + H2O = ADP-D-ribose + nicotinamide + H+, in a two step reaction: first an ADP-ribosyl cyclase reaction to synthesise cyclic ADP-ribose, followed by a cyclic ADP-ribose hydrolase reaction to generate (linear) ADP-ribose.