Reaction catalyzed by indole-3-glycerol-phosphate synthase (4.1.1.48)

		=			+			+		H2O
	1-(2-carboxyphenylamino)-1-deoxy-D-ribulose 5-phosphate	=		1-C-(indol-3-yl)glycerol 3-phosphate	+		CO2	+		H2O