查看文章

Abstract Properties of the amino acid sequence of the nematode myosin rod region, deduced from cloned DNA, are analysed. The rod sequence of 1117 residues contains a regular region of 1094 residues, which has features typical of an alpha-helical coiled coil, followed by a short non-helical tailpiece at the carboxyl end. The hydrophobic amino acids show the expected seven-residue pattern a, b, c, d, e, f, g, which is modulated by a longer repeat of 28-residue zones. In addition, there are four one-residue insertions, or skip residues, at the ends of zones, at positions 351, 548, 745 and 970. Myosin is considerably less hydrophobic than tropomyosin or alpha-keratin and the outer surface of the coiled coil is covered by clusters of positive and negatively charged amino acid side-chains. Molecular models suggest that the coiled coil is continuous throughout the rod, with an approximately uniform left-handed twist …