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bioRxiv · 10.1101/2023.02.02.526913

High-Resolution structures of microtubule-bound KIF1A and its pathogenic variant P305L

Benoit, M. P. M. H.·Rao, L.·Asenjo, A. B.·Gennerich, A.·Sosa, H. J.
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Abstract

Mutations in the microtubule-associated motor protein KIF1A lead to severe neurological conditions known as KIF1A-associated neurological disorders (KAND). Despite insights into its molecular mechanism, high-resolution structures of KIF1A-microtubule complexes remain undefined. Here, we present 2.7-3.4 [A] resolution structures of dimeric microtubule-bound KIF1A, including the pathogenic P305L mutant, across various nucleotide states. Our structures reveal that KIF1A binds microtubules in one- and two-heads-bound configurations, with both heads exhibiting distinct conformations with tight inter-head connection. Notably, KIF1As class-specific loop 12 (K-loop) forms electrostatic interactions with the C-terminal tails of both - and {beta}-tubulin. The P305L mutation does not disrupt these interactions but alters loop-12s conformation, impairing strong microtubule-binding. Structure-function analysis reveals the K-loop and head-head coordination as major determinants of KIF1As superprocessive motility. Our findings advance the understanding of KIF1As molecular mechanism and provide a basis for developing structure-guided therapeutics against KAND.

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Benoit, M. P. M. H., Rao, L., Asenjo, A. B., Gennerich, A., Sosa, H. J.. 2023-02-03. High-Resolution structures of microtubule-bound KIF1A and its pathogenic variant P305L. https://doi.org/10.1101/2023.02.02.526913

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