FIGURE 4.

Interactions of kinesin- and dynein-dynactin-decorated beads on encountering intersections plotted versus relative density of motors bound to the bead. (A) Bead cargos coated with kinesin at a variety of decoration densities showed similar statistics when traversing on the (i) overpass or (ii) underpass microtubule. In i the blue line indicates the average percentage of single molecules and beads passing for all kinesin densities. In ii, the green line indicates the average percentage of beads switching for all kinesin densities. (B) Bead cargos coated with dynein-dynactin show a large dependence on motor number when traversing on the overpass (i) or underpass (ii) microtubule. For all plots: passes (blue squares and lines), pauses (red diamonds and lines), switches (green triangles and lines), dissociation (orange stars and lines), and reversals (purple circles and lines); the leftmost symbols denote the single-molecule TIRF data for comparison. Dashed lines are drawn from the TIRF data to the bead data as a guide to the eye.