5.3.1.20	Co2+	divalent cation required, Km: 0.0004 mM	2645, 2648	
5.3.1.20	Mg2+	divalent cation required, Km: 0.018 mM	2645, 2648	
5.3.1.20	Mn2+	divalent cation required for activity, Mn2+ is the best activator, Km: 0.0001 mM	2645, 2648