8YY5

Kinesin-14 with AlF3 bound to 14 PF Microtubule

Summary for 8YY5

• Entry DOI: 10.2210/pdb8yy5/pdb
• EMDB information: 39667
• Descriptor: Tubulin alpha-1B chain, Tubulin beta chain, Protein claret segregational, ... (8 entities in total)
• Functional Keywords: kinesin motor proteins, force production, power stroke fluctuations, motor spring-like element, reversed motility, mechanochemical coupling, mechanical states, cell cycle
• Biological source: Drosophila melanogaster (fruit fly); More
• Total number of polymer chains: 4
• Total formula weight: 194795.35

Authors

Shibata, S.,Imasaki, T.,Shigematsu, H.,Endow, S.A.,Nitta, R. (deposition date: 2024-04-03, release date: 2025-10-08, Last modification date: 2026-04-22)

Primary citation

Shibata, S.,Wang, M.Y.,Imasaki, T.,Shigematsu, H.,Ugarte La Torre, D.,Wei, Y.,Jobichen, C.,Hagio, H.,Sivaraman, J.,Sugita, Y.,Endow, S.A.,Nitta, R.
Structural analysis of a motor with increased mechanical output reveals new transitions in kinesin microtubule motility.
Sci Rep, 16:487-487, 2026

PubMed Abstract: Kinesin motors use ATP to produce force in cells, yet the conformational changes that generate force remain uncertain. Here, we report structural and mechanistic insights into a minus-end-directed kinesin-14 that exhibits increased mechanical output – the variant motor binds microtubules more tightly and moves with faster velocity than wild type. High-resolution structures, together with molecular dynamics simulations, reveal previously unobserved transitions in the nucleotide hydrolysis cycle. ADP release, triggered by microtubule binding, is coupled to twisting of the central β-sheet and stabilization of the stalk prior to the power stroke. ATP binding induces stalk fluctuations and a swing of the neck mimic, an element analogous to the kinesin-1 neck linker, resembling neck linker docking in plus-end-directed kinesins. The power stroke, characterized by a large stalk rotation, is followed by motor detachment from microtubules. The subsequent recovery stroke occurs while the motor is bound to ADP and free Pi, accompanied by β-strand-to-loop transitions, or β-sheet melting, implying that β-sheet refolding facilitates Pi release. The observed twisting and melting identify the central β-sheet as the long-sought elastic element or spring required for motor force production. The transitions we observe in kinesin-14 may also apply to other kinesins – this remains to be tested.

PubMed: 41491787
DOI: 10.1038/s41598-025-28573-7

Experimental method

ELECTRON MICROSCOPY (3.99 Å)