Identity of the metal ligands in the manganese- and iron-containing superoxide dismutases

Alignment of the amino acid sequence of peptides obtained following digestion of Photobacterium leiognathi iron superoxide dismutase with the known sequence of Bacillus stearothermophilus manganese superoxide dismutase shows that the residues found to form ligands to the manganese are cnserved in the iron enzyme. This indicates that the metal ligands in both proteins are identical