A ROD PROBE REVEALS GAIT OF MYOSIN V

Myosin V is a linear molecular motor that moves cargos along actin filaments in a cell. It has two ‘feet’ (conventionally called ‘heads’ or ‘motor domains’), each attached to a long and relatively stiff ‘leg’ (traditionally called ‘neck’ or ‘lever arm’), and walks by alternately swinging forward its feet, apparently similar to a human. I describe the mechanisms of how the trailing foot, once lifted, accesses the next forward landing site on actin, which have been revealed by directly observing the leg motion of a walking myosin V through a micrometer-sized biological rod attached to its leg. Next, I discuss our previously proposed mechanism for the lifted foot attaching to the next forward binding site. Finally, I comment on the usefulness of a rod probe as an experimental tool.