Myosins are a large family of motor proteins found in eukaryotic tissues. They are responsible for actin-based motility. Structure and Function Domains Most myosin molecules are composed of both a head and a tail domain. The head domain binds the filamentous actin, and uses ATP hydrolysis to generate force and to "walk" along the filament towards the (+) end (with the exception of one family member, myosin VI, which moves towards the (-) end). The tail domain generally mediates interaction… (More on Myosin)