2.7.1.73 K+ increases activity, optimum concentration: 40 mM 641923 2.7.1.73 K+ the enzyme requires both Mg2+ and K+ 641925 2.7.1.73 Mg2+ enzyme requires both Mg2+ and K+ 641925 2.7.1.73 Mg2+ reaction is dependent on presence of divalent cation 641923 2.7.1.73 Mg2+ required, optimal concentration: 5 mM 641922 2.7.1.73 Mn2+ can partially replace Mg2+ in activation 641922