Determination of primary structure of heavy meromyosin region of walleye pollack myosin heavy chain by cDNA cloning

Primary structure of heavy meromyosin region of walleye pollack Theragra ch alcogramma myosin heavy chain was determined by cDNA cloning. By using one PCR product and five cDNA clones isolated from a lambda gt11-cDNA library f or the pollack dorsal muscle, a nucleotide sequence of 3,923 bp comprising 60 bp of 5'-untranslational region and 3,863 bp of coding region was determ ined. The deduced sequence of 1,287 amino acids showed considerably high ho mology to the corresponding regions of carp myosin (83%) and chicken and ra bbit myosins (both 79%). The sequences of the regions for the putative ATP- binding, actin-binding, and regulatory light chain-binding were well conser ved among the pollack, carp, chicken, and rabbit myosins (83-100% homology) . On the other hand, relatively low sequence homologies were seen in the es sential light chain-binding site (52-78%), junctions between 20-kDa and 50- kDa domains (27-33%) and 25-kDa and 50-kDa domains (53-57%) of subfragment- 1.