1.14.20.5	Fe2+	Fe2+-dependent enzyme	676365	
1.14.20.5	Fe2+	required for full activity, cannot be replaced by Mn2+, Co2+ or Ni2+	439113	
1.14.20.5	FeSO4	65% reduced activity without FeSO4	699792	
1.14.20.5	Iron	Fe2+ is required	685800