High-resolution structures of the molecular motors bound to their filamentous tracks have been studied mostly using the motor-filament complex, such as the kinesin-MT complex or myosin-actin-filament complexes, in which purified motor domains are bound to in vitro polymerized filaments. By cryo-EM imaging and computer image processing, 3D structures of kinesin-MT complexes have been reported at a resolution of ~1 nm. However, for dynein, the same methods have not been so successful, and relatively little is known about their structures in the MT-bound states.