4.2.3.9	Co2+	can substitute for Mg2+ over the concentration range of 0.16 -5.0 mM	644244	
4.2.3.9	Mg2+	-	644244, 678256, 679218, 680359, 682223, 682226, 694515, 705304	
4.2.3.9	Mg2+	divalent cation required, 5 mM Mg2+ preferred	644244	
4.2.3.9	Mg2+	enzyme utilizes a trinuclear magnesium cluster to trigger the departure of the diphosphate leaving group, thereby forming an allylic carbocation that typically reacts with one of the remaining sigma-bonds of the substrate	693062	
4.2.3.9	Mg2+	required	704204, 747103	
4.2.3.9	Mg2+	required for enzyme reaction	691962	
4.2.3.9	Mg2+	required, maximal activity at 3 mM	644238	
4.2.3.9	Mn2+	-	644244	
4.2.3.9	Mn2+	0.01 mM, can partially replace Mg2+, inhibition above	644238	
4.2.3.9	Mn2+	Mn2+ can replace Mg2+ at 0.1-0.2 mM	644244