6.2.1.33 Co2+ 77% of the activation with Mg2+ 778 6.2.1.33 Co2+ activates 780 6.2.1.33 Fe2+ 70% of the activation with Mg2+ 778 6.2.1.33 Mg2+ - 690987, 690988 6.2.1.33 Mg2+ maximal initial rate of catalysis is achieved with an Mg2+:ATP ratio of 1:0.66 to 1:1.33 778 6.2.1.33 Mg2+ required 778, 780, 781 6.2.1.33 Mn2+ 87% of the activation with Mg2+ 778 6.2.1.33 Mn2+ activates 780 6.2.1.33 Ni2+ 11% of the activation with Mg2+ 778 6.2.1.33 Zn2+ 23% of the activation with Mg2+ 778