4.99.1.3	Co2+	incorporates Co2+ over Fe2+	649817	
4.99.1.3	Co2+	insertion of cobalt into sirohydrochlorin	644512	
4.99.1.3	Fe2+	able to chelate	644512	
4.99.1.3	Fe2+	iron-sulfur center	652468	
4.99.1.3	Ni2+	able to chelate nickel	644512