KIF14 binds tightly to microtubules and adopts a rigor-like conformation.
Arora, K., Talje, L., Asenjo, A.B., Andersen, P., Atchia, K., Joshi, M., Sosa, H., Allingham, J.S., Kwok, B.H.(2014) J Mol Biol 426: 2997-3015
- PubMed: 24949858 
- DOI: https://doi.org/10.1016/j.jmb.2014.05.030
- Primary Citation of Related Structures:  
4OZQ - PubMed Abstract: 
The mitotic kinesin motor protein KIF14 is essential for cytokinesis during cell division and has been implicated in cerebral development and a variety of human cancers. Here we show that the mouse KIF14 motor domain binds tightly to microtubules and does not display typical nucleotide-dependent changes in this affinity. It also has robust ATPase activity but very slow motility. A crystal structure of the ADP-bound form of the KIF14 motor domain reveals a dramatically opened ATP-binding pocket, as if ready to exchange its bound ADP for Mg·ATP. In this state, the central β-sheet is twisted ~10° beyond the maximal amount observed in other kinesins. This configuration has only been seen in the nucleotide-free states of myosins-known as the "rigor-like" state. Fitting of this atomic model to electron density maps from cryo-electron microscopy indicates a distinct binding configuration of the motor domain to microtubules. We postulate that these properties of KIF14 are well suited for stabilizing midbody microtubules during cytokinesis.
Organizational Affiliation: 
Department of Biomedical and Molecular Sciences, Queen's University, 18 Stuart St., Rm. 652, Kingston, ON K7L 3 N6, Canada.