Engineering The Neck Hinge Reshapes The Processive Movement of Kinesin-3

Objective In kinesin-3, the neck coil correlates with the following segments to form an extended neck that contains a characteristic hinge diverse from a proline in KIF13B to a long flexible linker in KIF1A. The function of this neck hinge for controlling processive movement, however, remains unclear. Methods We made a series of modifications to the neck hinges of KIF13B and KIF1A and tested their movement using a single-molecule motility assay. Results In KIF13B, the insertion of flexible residues before or after the proline differentially impacts the processivity or velocity, while the removal of this proline increases the both. In KIF1A, the deletion of entire flexible neck hinge merely enhances the processivity. The engineering of these hinge-truncated necks of kinesin-3 into kinesin-1 similarly boosts the processive movement of kinesin-1. Conclusion The neck hinge in kinesin-3 controls its processive movement and proper modifications tune the motor motility, which provides a novel strategy to reshape the processive movement of kinesin motors.