Three Beads Are Better Than One

Kinesin-1 is a motor protein that carries cargoes along microtubules in neurons and other cells. It is one of the best understood molecular motors from the physical, chemical, and structural points of view. Kinesin takes 8-nm steps, moving from one tubulin dimer to the next toward the plus-, or fast-growing end, of a microtubule. The steps are driven by the hydrolysis of ATP with kinesin’s two motor domains moving in a coordinated,...