The misato protein contains three distinct, conserved domains, segments I, II and III. Segments I and III are common to Tubulins pfam00091, but segment II aligns with myosin heavy chain sequences from D. melanogaster (PIR C35815), rabbit (SP P04460), and human (PIR S12458). Segment II of misato is a major contributor to its greater length compared with the various tubulins. The most significant sequence similarities to this 54-amino acid region are from a motif found in the heavy chains of myosins from different organisms. A comparison of segment II with the vertebrate myosin heavy chains reveals that it is homologous to a myosin peptide in the hinge region linking the S2 and LMM domains. Segment II also contains heptad repeats which are characteristic of the myosin tail alpha-helical coiled-coils. This myosin-like homology may be due only to the fact that both myosin and Misato carry coiled-coils, which appear similar but are not necessarily homologous (Wood V, personal communication).