6TIU

DROSOPHILA GTP-TUBULIN Y222F MUTANT

Summary for 6TIU

• Entry DOI: 10.2210/pdb6tiu/pdb
• Related: 6TIS
• Descriptor: Tubulin alpha-1 chain, Tubulin beta-1 chain, Stathmin-4, ... (7 entities in total)
• Functional Keywords: microtubule, microtubule dynamics, microtule nucleation, cell cycle
• Biological source: Drosophila melanogaster (Fruit fly); More
• Total number of polymer chains: 5
• Total formula weight: 220299.40

Authors

Gigant, B. (deposition date: 2019-11-22, release date: 2021-01-27, Last modification date: 2024-01-24)

Primary citation

Ayukawa, R.,Iwata, S.,Imai, H.,Kamimura, S.,Hayashi, M.,Ngo, K.X.,Minoura, I.,Uchimura, S.,Makino, T.,Shirouzu, M.,Shigematsu, H.,Sekimoto, K.,Gigant, B.,Muto, E.
GTP-dependent formation of straight tubulin oligomers leads to microtubule nucleation.
J.Cell Biol., 220:-, 2021

PubMed Abstract: Nucleation of microtubules (MTs) is essential for cellular activities, but its mechanism is unknown because of the difficulty involved in capturing rare stochastic events in the early stage of polymerization. Here, combining rapid flush negative stain electron microscopy (EM) and kinetic analysis, we demonstrate that the formation of straight oligomers of critical size is essential for nucleation. Both GDP and GTP tubulin form single-stranded oligomers with a broad range of curvatures, but upon nucleation, the curvature distribution of GTP oligomers is shifted to produce a minor population of straight oligomers. With tubulin having the Y222F mutation in the β subunit, the proportion of straight oligomers increases and nucleation accelerates. Our results support a model in which GTP binding generates a minor population of straight oligomers compatible with lateral association and further growth to MTs. This study suggests that cellular factors involved in nucleation promote it via stabilization of straight oligomers.

PubMed: 33544140
DOI: 10.1083/jcb.202007033

Experimental method

X-RAY DIFFRACTION (3.571 Å)