Myosin III is an actin-based motor protein with protein kinase activity []. It has been shown to play a role in the vision process and in hearing in mammals [, ]. There are two paralogues of Myo3 in vertebrates, Myo3a and Myo3b, both known to be expressed in vertebrate retina and cochlea. They are thought to be crucial for photoreceptor and stereocilia ultrastructure maintenance []. Class III myosins are characterized by the presence of an N-terminal protein kinase domain before their motor head domain. They are unconventional myosins that do not form dimers []. The catalytic (head) domain has ATPase activity and belongs to the larger group of P-loop NTPases.