Investigation of the structural and dynamic basis of kinesin dissociation from microtubule by atomistic molecular dynamics simulations

Kinesin is a molecular motor that can step processively on microtubules via the hydrolysis of ATP molecules.An important factor characterizing the processivity of the kinesin motor is its dissociation from the microtubule.Here,using all-atom molecular dynamics simulations,we studied the dissociation process of the kinesin head in weak-microtubulebinding or ADP state from tubulin on the basis of the available high-resolution structural data for the head and tubulin.By analyzing the simulated snapshots of the structure of the head-tubulin complex we provided detailed structural and dynamic information for the dissociation process.We found that the dissociation of the head along different directions relative to the tubulin exhibits very different dynamic behaviors.Moreover,the potential forms or energy landscapes of the interaction between the head and tubulin along different directions were determined.The studies have important implications for the detailed molecular mechanism of the dissociation of the kinesin motor and thus are critical to the mechanism of its processivity.