Fig. 3. Deduced secondary structure for myomesin 1 domains in rat and chicken. From the deduced amino acid sequences, secondary structure features were determined for the rat (A) and chicken (B) EH domains, the My2 immunoglobulin-like repeat domain (C) and the My4 fibronectin III repeat domain (D). My2 and My4 were deduced from a full-length rat Myom1 cDNA assembled from GenBank AC103176.4 using full-length mouse sequence as a template. Algorithms used for secondary structure predictions were from Lasergene software (DNASTAR, Inc.) and included Garnier-Robson (G-R) and Chou-Fasman (C-F) for -helix, ß-sheet, turn and coil content, Eisenberg for - and ß-amphipathic regions, Kyte-Doolittle for the hydrophilicity plot, and Karpus-Shultz to identify flexible regions. The secondary structure pattern for rat EH was highly conserved in mouse and human (data not shown), while the chicken EH region had substantially higher -helical content and lower turn and coil content, rendering it with a lower flexibility index. The remainder of rat myomesin 1 is comprised of seven immunoglobulin-like repeats (My2, My3, My9, My10, My11, My12 and My13), with My2 shown as representative (C), and five fibronectin repeats (My4-My8), with My4 shown as representative (D). Immunoglobulin and fibronectin repeats are principally comprised of -helical and ß-sheet structure, respectively.