1.17.4.2 Ca2+ - 437897 1.17.4.2 Ca2+ absolutely dependent on 437893 1.17.4.2 Ca2+ markedly stimulates activity 437895 1.17.4.2 Co2+ class II enzymes contain cobalamin as cofactor 715085 1.17.4.2 Co2+ enzyme requires adenosylcobalamin as a cofactor, the Co ion is involved in the reaction 714185 1.17.4.2 Cs+ activating effect 437892 1.17.4.2 Fe2+ the class III enzymes contain 4Fe-4S clusters in the small beta-subunit 715085 1.17.4.2 K+ activating effect 437892 1.17.4.2 Li+ activating effect 437892 1.17.4.2 Mg2+ - 437891, 437897