Preliminary results for the primary structure of bacterioferritin of Escherichia coli.

Bacterioferritins are type-b cytochromes which resemble ferritin. Amino acid analysis combined with chemical modification and partial sequence analysis characterize bacterioferritin of Escherichia coli in terms of its primary structure. It is a protein composed of one kind of polypeptide chain that commences with methionine and terminates with glutamic acid. The length of the polypeptide chain is, tentatively, 146 residues. Besides the N-terminal methionine residue there are three more methionine residues, which yield four CNBr peptides, which have been aligned. The identity of the following positions in the sequence has been ascertained: residues 1-25, 30-37, 83-88, 127-132 and 143-146. No homology with ferritin was found.