6TF9

Structure of the vertebrate gamma-Tubulin Ring Complex

これはPDB形式変換不可エントリーです。

6TF9 の概要

• エントリーDOI: 10.2210/pdb6tf9/pdb
• EMDBエントリー: 10491
• 分子名称: Helix 1, Gamma-tubulin complex component 3 homolog, Gamma-tubulin complex component 2, ... (17 entities in total)
• 機能のキーワード: gamma-tubulin ring complex, microtubule nucleation, cell cycle
• 由来する生物種: Xenopus laevis (African clawed frog); 詳細
• タンパク質・核酸の鎖数: 48
• 化学式量合計: 2273118.47

構造登録者

Zupa, E.,Pfeffer, S. (登録日: 2019-11-13, 公開日: 2019-12-11, 最終更新日: 2024-05-22)

主引用文献

Liu, P.,Zupa, E.,Neuner, A.,Bohler, A.,Loerke, J.,Flemming, D.,Ruppert, T.,Rudack, T.,Peter, C.,Spahn, C.,Gruss, O.J.,Pfeffer, S.,Schiebel, E.
Insights into the assembly and activation of the microtubule nucleator gamma-TuRC.
Nature, 578:467-471, 2020

PubMed Abstract: Microtubules are dynamic polymers of α- and β-tubulin and have crucial roles in cell signalling, cell migration, intracellular transport and chromosome segregation. They assemble de novo from αβ-tubulin dimers in an essential process termed microtubule nucleation. Complexes that contain the protein γ-tubulin serve as structural templates for the microtubule nucleation reaction. In vertebrates, microtubules are nucleated by the 2.2-megadalton γ-tubulin ring complex (γ-TuRC), which comprises γ-tubulin, five related γ-tubulin complex proteins (GCP2-GCP6) and additional factors. GCP6 is unique among the GCP proteins because it carries an extended insertion domain of unknown function. Our understanding of microtubule formation in cells and tissues is limited by a lack of high-resolution structural information on the γ-TuRC. Here we present the cryo-electron microscopy structure of γ-TuRC from Xenopus laevis at 4.8 Å global resolution, and identify a 14-spoked arrangement of GCP proteins and γ-tubulins in a partially flexible open left-handed spiral with a uniform sequence of GCP variants. By forming specific interactions with other GCP proteins, the GCP6-specific insertion domain acts as a scaffold for the assembly of the γ-TuRC. Unexpectedly, we identify actin as a bona fide structural component of the γ-TuRC with functional relevance in microtubule nucleation. The spiral geometry of γ-TuRC is suboptimal for microtubule nucleation and a controlled conformational rearrangement of the γ-TuRC is required for its activation. Collectively, our cryo-electron microscopy reconstructions provide detailed insights into the molecular organization, assembly and activation mechanism of vertebrate γ-TuRC, and will serve as a framework for the mechanistic understanding of fundamental biological processes associated with microtubule nucleation, such as meiotic and mitotic spindle formation and centriole biogenesis.

PubMed: 31856152
DOI: 10.1038/s41586-019-1896-6

実験手法

ELECTRON MICROSCOPY (4.8 Å)