Comparison of overlapping secondary structure in kinesin and myosin. Image courtesy of R. Vale, The University of California, San Francisco. USA.
The members of the kinesin superfamily are ATP-driven motor proteins that are responsible for the movement of many cargoes along microtubules. The microtubules comprise a bundle of protofilaments, each of which is a long polymer of 
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-tubulin heterodimers arranged in head-to-tail fashion. Although the activity of kinesins is crucial in processes such as vesicular transport and chromosome segregation, their existence was unknown before 1985, and the details of their interaction with microtubules were not understood until the mid-1990s, when it became easier to purify recombinant versions of the motor domains.
In 1995, a series of structural studies provided a basis for investigating how kinesins generate directed movement along a microtubule. Three-dimensional electron microscopy (EM) studies by Kikkawa et al., Hirose et al. and Hoenger et al. provided the first views of interactions between microtubules and a single motor-domain head from kinesin proteins. Despite the low resolution, the studies revealed that kinesin preferentially bound to one of the two subunits within the tubulin heterodimer. Earlier cross-linking studies indicated that it was most likely to be -tubulin, and this was confirmed by later higher resolution cryo-EM studies. Hoenger et al. found that kinesin binding induced small structural changes on the microtubule. All of the studies indicated that the kinesin travels along a single protofilament. Hirose et al. also found that the kinesin motor domain undergoes conformational changes during the ATPase cycle.
...a series of structural studies provided a basis for investigating how kinesins generate directed movement along a microtubule.
A year later, Kull et al. determined the crystal structure of a kinesin motor domain bound to ADP. Surprisingly, this structure included a folding motif that is present in the core of the myosin head—the actin-associated motor protein—primarily around the catalytic site. It was then proposed that the mechanism of energy transduction was similar but that structural differences farther away from the active site would require each protein to use different strategies to transduce ATP hydrolysis to the large conformational motions associated with directed motor movement.
The structural details of the microtubule were shown at near-atomic resolution only a few years later, when Nogales et al. docked a previously determined structure of the /-tubulin heterodimer into an intermediate-resolution cryo-EM reconstruction of the microtubule polymer. The resulting model revealed regions of tubulin involved in interactions within and between protofilaments, and also confirmed the assignment of protofilament polarity, with -tubulin and -tubulin being found at plus and minus ends, respectively.
Collectively, these studies have served as the basis for understanding interactions between microtubules and their associated proteins, how directed cargo movement along the microtubule is achieved and how polymer growth might be regulated.
