3.6.1.41	Ca2+	no effect	246770	
3.6.1.41	Ca2+	weak stimulation in absence of other divalent metal ions, high synergistic stimulation in combination with Co2+ at its suboptimal concentration	246765	
3.6.1.41	Cd2+	0.002-0.005 mM, 3.5fold stimulation	246765	
3.6.1.41	Co2+	0.1-0.5 mM, 100fold increase of activity	246765	
3.6.1.41	Co2+	2500fold stimulation	246770	
3.6.1.41	Co2+	about 50% of the activity with Mn2+. In the presence of Mn2+, PrpA hydrolyzes P1,P5-bis(adenosyl)tetraphosphate mainly into AMP and ATP, whereas in the presence of Co2+ PrpA hydrolyzes P1,P5-bis(adenosyl)tetraphosphate into two molecules of ADP, reaction of EC 3.6.1.17	733872	
3.6.1.41	Co2+	required for ApnA hydrolysis	733872	
3.6.1.41	Co2+	symmetrical Ap4A hydrolase is Co2+-dependent	697896	
3.6.1.41	Mg2+	weak stimulation in absence of other divalent metal ions, high synergistic stimulation in combination with Co2+ at its suboptimal concentrations	246765	
3.6.1.41	Mn2+	0.2-0.5 mM, 8fold stimulation	246765	
3.6.1.41	Mn2+	900fold stimulation	246770	
3.6.1.41	Mn2+	best activator. In the presence of Mn2+, PrpA hydrolyzes P1,P5-bis(adenosyl)tetraphosphate mainly into AMP and ATP, whereas in the presence of Co2+ PrpA hydrolyzes P1,P5-bis(adenosyl)tetraphosphate into two molecules of ADP, reaction of EC 3.6.1.17	733872	
3.6.1.41	Ni2+	0.004-0.008 mM, 3.5fold stimulation	246765