3.6.1.64	Mg2+	maximum activity at 1 mM	720583	
3.6.1.64	additional information	divalent cation absolutely required. No IDP hydrolysis in the presence of 5mM Mn2+, Co2+ or Ca2+	720583	
3.6.1.64	Zn2+	may partly substitue for Mn2+	720583