We propose a dynamic mechanism for the processive motility of dynein on microtubules (MTs). The force generated for the motion of dynein is purely mechanical in origin. When a dynein monomer binds to a MT, the AAA rin...We propose a dynamic mechanism for the processive motility of dynein on microtubules (MTs). The force generated for the motion of dynein is purely mechanical in origin. When a dynein monomer binds to a MT, the AAA ring of dynein might fit into one of the trenches on the outer surface of the MT, with the linker domain leaning on the ratchet-shaped protofilament. At room temperature, the dynein molecule exhibits random thermal motion on the outer surface of the MT. The collision between the asymmetric ratchet teeth and the linker exerts a reactive impulsive force on the dynein molecule. The probability of producing an impulse with a longitudinal component pointing to either end of the MT depends on the instantaneous motion of dynein, the shape of the linker, and the mass distribution of the dynein with/without a load. In the dynamic mechanism, dynein monomers can move independently and processively toward either end of the MT. Many observations of the motility of dynein can be reproduced in a simulation system.展开更多
文摘We propose a dynamic mechanism for the processive motility of dynein on microtubules (MTs). The force generated for the motion of dynein is purely mechanical in origin. When a dynein monomer binds to a MT, the AAA ring of dynein might fit into one of the trenches on the outer surface of the MT, with the linker domain leaning on the ratchet-shaped protofilament. At room temperature, the dynein molecule exhibits random thermal motion on the outer surface of the MT. The collision between the asymmetric ratchet teeth and the linker exerts a reactive impulsive force on the dynein molecule. The probability of producing an impulse with a longitudinal component pointing to either end of the MT depends on the instantaneous motion of dynein, the shape of the linker, and the mass distribution of the dynein with/without a load. In the dynamic mechanism, dynein monomers can move independently and processively toward either end of the MT. Many observations of the motility of dynein can be reproduced in a simulation system.
