2.7.1.27	Ca2+	19% as effective as Mg2+	641258	
2.7.1.27	Mg2+	optimal Mg2+/ATP ratio: 2/1, 15% and 11% inhibition at ratios of 5/1 and 1/1, respectively	641258	
2.7.1.27	Mn2+	57% as effective as Mg2+	641258