  Motor proteins display widely different stepping patterns as they move on
microtubule tracks, from the deterministic linear or helical motion performed
by the protein kinesin to the uncoordinated random steps made by dynein. How
these different strategies produce an efficient navigation system needed to
ensure correct cellular functioning is still unclear. Here, we show by
numerical simulations that deterministic and random motor steps yield different
outcomes when random obstacles decorate the microtubule tracks: kinesin moves
faster on clean tracks but its motion is strongly hindered on decorated tracks,
while dynein is slower on clean tracks but more efficient in avoiding
obstacles. Further simulations indicate that dynein's advantage on decorated
tracks is due to its ability to step backwards. Our results explain how
different navigation strategies are employed by the cell to optimize motor
driven cargo transport.
