The primary structure of iron superoxide dismutase from Escherichia coli

The complete amino acid sequence of iron superoxide from Escherichia colihas been determined. The sequence was deduced from analysis of peptides obtained after cleavage of the carboxymethylated apoenzyme with trypsin, Stapholococcus aureusprotease or CNBr. The polypeptide chain is made up of 192 residues and is easily aligned with the other known amino acid sequences of iron and manganese superoxide dismutases from various sources. The iron superoxide dismutase from E. colishows a significantly higher homology with the iron enzyme from a different organism than with the manganese isoenzyme from E. coli.