3.1.13.1	Ca2+	may partly substitute for Mg2+, with less efficiency	730689	
3.1.13.1	K+	100 mM KCl stimulating	134058	
3.1.13.1	K+	activating	134050, 134055	
3.1.13.1	K+	activation against poly(A), -(U), -(C), RNA and T4 mRNA	134052	
3.1.13.1	K+	maximum concentration for activation: 0.15 mM at pH 7.4 and 8.0	134055	
3.1.13.1	K+	necessary for activity	134049, 134057	
3.1.13.1	K+	optimum for poly(A) as substrate: 100 mM	134057	
3.1.13.1	K+	optimum for poly(C) as substrate: 25 mM	134057	
3.1.13.1	K+	required	656710	
3.1.13.1	K+	required for activity	666793	
3.1.13.1	KCl	preferred concentration is 50 mM. Activity starts to decrease above 150 mM	730689	
3.1.13.1	Li+	can substitute for K+ to a small extend	134052	
3.1.13.1	Mg2+	-	700000	
3.1.13.1	Mg2+	Asp209, but not Asp207, contacting Mg2+ in addition to Asp201, Asp210, and the phosphate group of nt 13	693048	
3.1.13.1	Mg2+	dependent on	716841	
3.1.13.1	Mg2+	for catalysis of mRNA but not for substrate binding	664891	
3.1.13.1	Mg2+	increases activity	656668	
3.1.13.1	Mg2+	is important for substrate binding of RNase R in the channel as well as for catalysis. Asp278 is predicted to coordinate a Mg2+ at the catalytic center of RNase R	698974	
3.1.13.1	Mg2+	necessary for activity	134049, 134050, 134051, 134053, 134054, 134057, 134058, 134063	
3.1.13.1	Mg2+	optimum: 1 mM	134053	
3.1.13.1	Mg2+	optimum: 1-2 mM	134057	
3.1.13.1	Mg2+	optimum: 1.5 mM	134054	
3.1.13.1	Mg2+	optimum: 2 mM	134051	
3.1.13.1	Mg2+	required	656710	
3.1.13.1	Mg2+	required for activity	666793	
3.1.13.1	Mg2+	required for activity, preferred concntration is 1 mM	730689	
3.1.13.1	Mg2+	required for the catalysis	709032	
3.1.13.1	Mg2+	required, 5-20 mM optimal concentration	657199	
3.1.13.1	Mg2+	required, no degradation of the RNA occurs in the absence of Mg2+	751728	
3.1.13.1	Mn2+	can partially replace Mg2+	134053, 134058	
3.1.13.1	Mn2+	increases activity	656668	
3.1.13.1	Mn2+	necessary for activity	134049, 134054	
3.1.13.1	Mn2+	optimum: 0.3 mM, stimulation about two-thirds the rate with Mg2+	134054	
3.1.13.1	Na+	increases activity against T4 mRNA, can substitute for K+ in activation against T4 mRNA and RNA	134052	
3.1.13.1	NaCl	enzyme is active in NaCl, but the cleavage efficiency is 10times lower when compared to its activity in KCl	730689	
3.1.13.1	NH4+	activating	134050, 134052, 134054	
3.1.13.1	NH4+	can substitute for K+ to a small extend	134050, 134052, 134055	
3.1.13.1	NH4+	stimulates at pH 9.5 about 100%, optimum: 50 mM	134054	
3.1.13.1	Zn2+	induces a folding reaction resulting in protein preparations with 50-60% alpha-helical content and 10-20% beta-sheet structure, critical concentration for refolding bigger or equal to 0.1 mM	666317