. "Catalysis of the reaction: diphosphate + nicotinamide mononucleotide = 5-phospho-alpha-D-ribose 1-diphosphate + H(+) + nicotinamide." . . "nicotinamide phosphoribosyltransferase activity" . "nicotinamide mononucleotide pyrophosphorylase activity" . "nicotinamide mononucleotide synthetase activity" . "nicotinamide-nucleotide:diphosphate phospho-alpha-D-ribosyltransferase activity" . "NMN diphosphorylase activity" . "NMN pyrophosphorylase activity" . "NMN synthetase activity" . . .