Aa6

A. australis Hc subunits belong to eight different polypeptide chains. They are prefixed Aa and numbered 1, 2, 3A, 3B, 3C, 4, 5A, 5B, 6 in increasing order of electrophoretic mobility. Subunit Aa1 is heterodimeric (Aa3C-5B), whereas all the others are monomers. Each monomeric subunit is a kidney-shaped structure with three structural domains, the N-terminal, central and C-terminal domains as described for Panulirus interruptus hemocyanin. Subunit Aa6 exists as four copies, with one copy at each of the four corners of the molecule in the top orientation. Aa6 has been well characterized and purified from the entire Hc.