Complete nucleotide sequence of a cDNA encoding a myosin heavy chain from mantle tissue of scallop Patinopecten yessoensis

ABSTRACT: It has been reported that the amino acid sequences of striated and catch muscle myosin heavy chains from two scallop species ( Argopecten irradians and Placopecten magellanicus ) are almost identical, but that the ATPase activities between these myosins vary several-fold. These myosin sequences have been useful for identifying the region that modulates the ATPase activity of scallop myosin. In the present study, a cDNA encoding a myosin heavy chain was isolated from the mantle tissue of scallop Patinopecten yessoensis . The cDNA is composed of 6067 base pairs (bp) including an open-reading frame of 5841 p, which encodes an amino acid sequence of 1947 residues. The deduced amino acid sequence of P. yessoensis mantle myosin had a high identity of 90%, 92%, and 91% to P. magellanicus , A. irradians , and Pecten maximus striated muscle myosins, respectively. Interestingly, while the deduced amino acid sequences of around adenosine triphosphate-binding and actin-binding sites of the mantle myosin are homologous to those of A. irradians striated muscle myosin, the subfragment 2 hinge region and the non-helical tail region are similar to those of catch muscle myosin.