Reaction catalyzed by nicotinate-nucleotide-dimethylbenzimidazole phosphoribosyltransferase (2.4.2.21)

		+			=			+
	nicotinic acid mononucleotide	+		benzimidazole	=		1-alpha-D-ribofuranosylbenzimidazole 5'-phosphate	+		nicotinate