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bioRxiv · 10.1101/2023.03.06.531442

Cryo-EM of α-tubulin isotype containing microtubules revealed a contracted structure of α4A/β2A microtubules

Diao, L.·Zheng, W.·Zhao, Q.·Liu, M.·Fu, Z.·Zhang, X.·Bao, L.·Cong, Y.
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Abstract

Microtubules are hollow /{beta}-tubulin heterodimeric polymers playing critical roles in cells. In vertebrates, both - and {beta}-tubulin have multiple isotypes encoded by different genes, which are intrinsic factors in regulating microtubule functions. However, structures of microtubules composed of different tubulin isotypes, especially -tubulin isotypes, remain largely unknown. Here, we purified recombinant tubulin heterodimers composed of different mouse -tubulin isotypes, including 1A, 1C and 4A, with {beta}-tubulin isotype {beta}2A. We further assembled and determined the cryo-electron microscopy (cryo-EM) structures of 1A/{beta}2A, 1C/{beta}2A, and 4A/{beta}2A microtubules. Our structural analysis demonstrated that 4A/{beta}2A microtubules exhibit a longitudinal contraction between tubulin interdimers compared with 1A/{beta}2A and 1C/{beta}2A microtubules. Collectively, our findings reveal that -tubulin isotype composition could tune microtubule structures, and also provide evidence for the "tubulin code" hypothesis.

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Diao, L., Zheng, W., Zhao, Q., Liu, M., Fu, Z., Zhang, X., Bao, L., Cong, Y.. 2023-03-07. Cryo-EM of α-tubulin isotype containing microtubules revealed a contracted structure of α4A/β2A microtubules. https://doi.org/10.1101/2023.03.06.531442

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