Amino Acid Sequence of the Hemerythrin α Subunit from Lingula unguis

The amino acid sequence of the α subunit of the allosteric hemerythrin from Lingula unguis was determined. It consists of 117 amino acid residues. Compared with other non-allosteric hemerythrins consisting of identical subunits of 113 amino acid residues, this protein has the deletion of the N-terminal amino acid and the insertion of five amino acids in the same region as in the case of the monomeric myoerythrin from Themiste zostericola. As the amino acid sequence of the β subunit has also been determined [Yano, H., Satake, K., Ueno, Y., & Tsugita, A. Protein Sequence and Data Analysis, in press], the complete sequence analysis of an allosteric hemerythrin has been accomplished for the first time. The difference in the octameric structures of allosteric and non-allosteric hemerythrins are discussed.