X-ray and Cryo-EM structures reveal mutual conformational changes of Kinesin and GTP-state microtubules upon bindingMorikawa, M., Yajima, H., Nitta, R., Inoue, S., Ogura, T., Sato, C., Hirokawa, N.
(2015) Embo J. --: --
- PubMed: 25777528
- DOI: 10.15252/embj.201490588
- Primary Citation of Related Structures:  3WRD, 3X2T
- PubMed Abstract:
The molecular motor kinesin moves along microtubules using energy from ATP hydrolysis in an initial step coupled with ADP release. In neurons, kinesin-1/KIF5C preferentially binds to the GTP-state microtubules over GDP-state microtubules to selective ...
The molecular motor kinesin moves along microtubules using energy from ATP hydrolysis in an initial step coupled with ADP release. In neurons, kinesin-1/KIF5C preferentially binds to the GTP-state microtubules over GDP-state microtubules to selectively enter an axon among many processes; however, because the atomic structure of nucleotide-free KIF5C is unavailable, its molecular mechanism remains unresolved. Here, the crystal structure of nucleotide-free KIF5C and the cryo-electron microscopic structure of nucleotide-free KIF5C complexed with the GTP-state microtubule are presented. The structures illustrate mutual conformational changes induced by interaction between the GTP-state microtubule and KIF5C. KIF5C acquires the 'rigor conformation', where mobile switches I and II are stabilized through L11 and the initial portion of the neck-linker, facilitating effective ADP release and the weak-to-strong transition of KIF5C microtubule affinity. Conformational changes to tubulin strengthen the longitudinal contacts of the GTP-state microtubule in a similar manner to GDP-taxol microtubules. These results and functional analyses provide the molecular mechanism of the preferential binding of KIF5C to GTP-state microtubules.
Department of Cell Biology and Anatomy, The University of Tokyo, Hongo Tokyo, Japan Department of Molecular Structure and Dynamics, Graduate School of Medicine, The University of Tokyo, Hongo Tokyo, Japan.