Identification of key residues that regulate the interaction of kinesins with microtubule ends.

Kinesins are molecular motors that use energy derived from ATP turnover to walk along microtubules, or when at the microtubule end, regulate growth or shrinkage. All kinesins that regulate microtubule dynamics have long residence times at microtubule ends, whereas those that only walk have short end-residence times. Here, we identify key amino acids involved in end binding by showing that when critical residues from Kinesin-13, which depolymerises microtubules, are introduced into Kinesin-1, a walking kinesin with no effect on microtubule dynamics, the end-residence time is increased up to several-fold. This indicates that the interface between the kinesin motor domain and the microtubule is malleable and can be tuned to favour either lattice or end binding.