6.3.2.32 Mg2+ the CofF protein strictly requires a divalent metal ion for ligase activity. CofF enzyme incubated with 10 mM MgCl2 has about 33% of the activity supported by 10 mM MnCl2 700925 6.3.2.32 Mn2+ the CofF protein strictly requires a divalent metal ion for ligase activity. CofF enzyme incubated with 10 mM MgCl2 has about 33% of the activity supported by 10 mM MnCl2 700925