The sequence of an embryonic myosin heavy chain gene and isolation of its corresponding cDNA

The complete sequence of an embryonic chicken myosin heavy chain has been determined. Introns and exons were identified by comparison with the corresponding cDNA. The cDNA contains 5,962 bases, of which 85 bases constitute the poly(A) tail. The cDNA represents the entire mRNA transcript, except for 90 bases at the 5'-coding terminus and 101 bases of the 5'-untranslated region. The gene's coding region is split by 37 introns; two additional introns split the 101 base pairs which make up the 5'-untranslated region. The complete gene is approximately 23,000 base pairs and encodes a protein whose molecular weight is 222,559 and consists of 1,940 amino acids. Analysis of the protein and comparison with other myosin sequences reveal that certain regions have been conserved; those amino acids which have been postulated to participate in the ATPase and actin-binding activities of the molecule are highly homologous. These comparisons have allowed the identification of isolated regions within the myosin heavy chain that appear to be essential for the molecule's function.