Transferrin: internal homology in the amino acid sequence

Science  26 Dec 1975:
Vol. 190, Issue 4221, pp. 1306-1307
DOI: 10.1126/science.1198114


Two regions of the primary structure of human serum transferrin, of 87 and 57 residues, are reported. When these are suitably aligned by placing two gaps, 40 percent of the amino acids in corresponding positions are identical. This indicates that the doubling of an ancestral structural gene occurred during the evolution of the transferrins.