Cryo-EM structure of the Ustilago maydis kinesin-5 motor domain bound to microtubules.von Loeffelholz, O., Ann Moores, C.
(2019) J Struct Biol
- PubMed: 31288039
- DOI: 10.1016/j.jsb.2019.07.003
- Primary Citation of Related Structures:
- PubMed Abstract:
In many eukaryotes, kinesin-5 motors are essential for mitosis, and small molecules that inhibit human kinesin-5 disrupt cell division. To investigate whether fungal kinesin-5s could be targets for novel fungicides, we studied kinesin-5 from the path ...
In many eukaryotes, kinesin-5 motors are essential for mitosis, and small molecules that inhibit human kinesin-5 disrupt cell division. To investigate whether fungal kinesin-5s could be targets for novel fungicides, we studied kinesin-5 from the pathogenic fungus Ustilago maydis. We used cryo-electron microscopy to determine the microtubule-bound structure of its motor domain with and without the N-terminal extension. The ATP-like conformations of the motor in the presence or absence of this N-terminus are very similar, suggesting this region is structurally disordered and does not directly influence the motor ATPase. The Ustilago maydis kinesin-5 motor domain adopts a canonical ATP-like conformation, thereby allowing the neck linker to bind along the motor domain towards the microtubule plus end. However, several insertions within this motor domain are structurally distinct. Loop2 forms a non-canonical interaction with α-tubulin, while loop8 may bridge between two adjacent protofilaments. Furthermore, loop5 - which in human kinesin-5 is involved in binding allosteric inhibitors - protrudes above the nucleotide binding site, revealing a distinct binding pocket for potential inhibitors. This work highlights fungal-specific elaborations of the kinesin-5 motor domain and provides the structural basis for future investigations of kinesins as targets for novel fungicides.
Institute of Structural and Molecular Biology, Birkbeck College, London WC1E 7HX, UK. Electronic address: email@example.com.