Sequence analysis of the complete Caenorhabditis elegans myosin heavy chain gene family.
The sequences of three myosin heavy chain (MHC) genes from Caenorhabditis elegans, myo-1, 2 and 3, are presented. These genes, together with unc-54, comprise the entire nematode sacromeric MHC family. Comparison of nematode MHC sequences and sarcomeric, smooth and non-muscle MHCs from other organisms highlights conserved sequence features of the MHC rod believed to be important for thick filament assembly. These include: conservation of sequence differences between individual 28 amino acid repeats; invariant placements of large aromatic residues, such as tryptophan, in the rod sequences; conservation of "weak spots" in the hydrophobic seam; and conservation of non-uniform charge distributions along the length of the rod. The rod sequences of the body wall isoforms A and B are more closely related to each other than to the pharyngeal isoforms C and D, suggesting that structural constraints have been imposed by their location within the same thick filament. We have also identified the major transcriptional start site for gene unc-54. Surprisingly, there are no TATA or other known transcription factor elements immediately upstream from the unc-54 start site, or in the upstream regions of the other genes of the C. elegans MHC gene family.
Dibb
N J
NJ
M.R.C. Laboratory of Molecular Biology, University Postgraduate Medical School, Cambridge, U.K.
Maruyama
I N
IN
Krause
M
M
Karn
J
J
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002107:Caenorhabditis / Q000235:genetics*; D003062:Codon; D005796:Genes; D008969:Molecular Sequence Data; D009218:Myosins / Q000235:genetics*; D014158:Transcription, Genetic
D003062:Codon; D009218:Myosins