3.1.13.4	Ba2+	activates	134089	
3.1.13.4	Ba2+	less effective than Mg2+ or Mn2+	134089	
3.1.13.4	Ca2+	activates	134089	
3.1.13.4	Ca2+	less effective than Mg2+ or Mn2+	134089	
3.1.13.4	Cd2+	2 mM, activates reaction, can modulated the substrate length requirement	669291	
3.1.13.4	Co2+	2 mM, activates reaction, can modulated the substrate length requirement	669291	
3.1.13.4	Co2+	activates	134089	
3.1.13.4	Co2+	less effective than Mg2+ or Mn2+	134089	
3.1.13.4	Cu2+	activates	134089	
3.1.13.4	Cu2+	less effective than Mg2+ or Mn2+	134089	
3.1.13.4	Fe2+	can substitute for Mg2+, Mn2+, optimal at 0.01 mM, two binding sites	652348	
3.1.13.4	K+	K+ is essential to PARN activity and acts as an allosteric activator of PARN with multiple binding sites. K+ induces additional regular secondary structures and enhances PARN stability against heat-induced inactivation, unfolding and aggregation	749789	
3.1.13.4	K+	required	714476, 714876	
3.1.13.4	K+	required, optimal around 100 mM	652023	
3.1.13.4	K+	required, optimal at about 100 mM	653131	
3.1.13.4	K+	the binding of K+ to the entire RNA-recognition motif domain, which plays a central role in the allosteric communications of PARN regulation, leads to an increase of substrate-binding affinity but a decrease in the cooperativity of the substrate-binding site, while the binding of the cap analogue decreases both the catalytic efficiency and the substrate-binding affinity	690777	
3.1.13.4	K3PO4	absolute required in absence of spermidine	134096	
3.1.13.4	Mg2+	2 mM, activates reaction, can modulated the substrate length requirement	669291	
3.1.13.4	Mg2+	active site consists of two metal ions (MgA and MgB), residue D50 takes a central position by contacting both metal ions. MgA is also coordinated by E52 and D240, while D171 contacts MgB. Seven water molecules, three associated with MgA and four with MgB, complete the dual octahedral coordination spheres of the two ions	682172	
3.1.13.4	Mg2+	can be replaced by Mn2+	134089	
3.1.13.4	Mg2+	can protect PARN against thermal inactivation by increasing the midpoint of inactivation and decreasing the inactivation rate, protective effect is unique to Mg2+ in a concentration-dependent manner	679848	
3.1.13.4	Mg2+	divalent cation required around 1 mM, Mg2+ being most effective	652023	
3.1.13.4	Mg2+	essential for PARN activity and stability	690777	
3.1.13.4	Mg2+	nocturnin nuclease activity is magnesium dependent	756528	
3.1.13.4	Mg2+	optimal activity at 3 mM	134089	
3.1.13.4	Mg2+	or Mn2+, required	652348	
3.1.13.4	Mg2+	required	134089, 652522, 714476, 714876, 715505, 749789, 751734, 751744, 752164	
3.1.13.4	Mg2+	required, optimal at about 1 mM, preferred kind of divalent cation	653131	
3.1.13.4	Mg2+	required, the active site of PARN contains four conserved acidic amino acid residues, D28, E30, D292 and D382, the latter being the most important, that coordinate two Mg2+ ions and are essential for the catalytic activity. These acidic residues form a negative charge cave that can bind with two Mg2+ ions. Cofactor Mg2+ is also important to PARN stability against inactivation induced by heat treatment, but promotes thermal aggregation at high temperatures. Mg2+ significantly decreases the rate but increases the aggregate size of the 54 kDa wild-type enzyme in a concentration-dependent manner. The metal cofactor binding or mutation induces changes in the microenvironments around Trp residues	715205	
3.1.13.4	Mg2+	the deadenylase activity of CNOT6L is strictly dependent on the presence of Mg2+	714829	
3.1.13.4	Mg2+	two Mg2+ ions present in the active sites of the ribonucleases of multi-subunit Ccr4-Not deadenylase and are required for RNA cleavage	750054	
3.1.13.4	Mn2+	2 mM, activates reaction	669291	
3.1.13.4	Mn2+	can be replaced by Mg2+	134089	
3.1.13.4	Mn2+	may partly substitute for Mg2+, 17% of activity detected with Mg2+	652023	
3.1.13.4	Mn2+	Mn2+ together with Mg2+ creates a fast and non-specific enzyme	682172	
3.1.13.4	Mn2+	optimal activity at 0.5 mM	134089	
3.1.13.4	Mn2+	or Mg2+, required	652348	
3.1.13.4	Mn2+	required	134089	
3.1.13.4	additional information	no activtiy with Zn2+, Ca2+	652023	
3.1.13.4	additional information	PARN is a divalent metal ion-dependent 3'-exonuclease	694441	
3.1.13.4	Na+	may substitute for K*, less effective	652023	
3.1.13.4	Na+	may substitute for K+, but less effective	653131	
3.1.13.4	Sn2+	activates	134089	
3.1.13.4	Sn2+	less effective than Mg2+ or Mn2+	134089	
3.1.13.4	Zn2+	2 mM, activates reaction	669291	
3.1.13.4	Zn2+	activates	134089	
3.1.13.4	Zn2+	less effective than Mg2+ or Mn2+	134089