+Search query
-Structure paper
Title | Structure of the native γ-tubulin ring complex capping spindle microtubules. |
---|---|
Journal, issue, pages | Nat Struct Mol Biol, Vol. 31, Issue 7, Page 1134-1144, Year 2024 |
Publish date | Apr 12, 2024 |
Authors | Tom Dendooven / Stanislau Yatskevich / Alister Burt / Zhuo A Chen / Dom Bellini / Juri Rappsilber / John V Kilmartin / David Barford / |
PubMed Abstract | Microtubule (MT) filaments, composed of α/β-tubulin dimers, are fundamental to cellular architecture, function and organismal development. They are nucleated from MT organizing centers by the ...Microtubule (MT) filaments, composed of α/β-tubulin dimers, are fundamental to cellular architecture, function and organismal development. They are nucleated from MT organizing centers by the evolutionarily conserved γ-tubulin ring complex (γTuRC). However, the molecular mechanism of nucleation remains elusive. Here we used cryo-electron tomography to determine the structure of the native γTuRC capping the minus end of a MT in the context of enriched budding yeast spindles. In our structure, γTuRC presents a ring of γ-tubulin subunits to seed nucleation of exclusively 13-protofilament MTs, adopting an active closed conformation to function as a perfect geometric template for MT nucleation. Our cryo-electron tomography reconstruction revealed that a coiled-coil protein staples the first row of α/β-tubulin of the MT to alternating positions along the γ-tubulin ring of γTuRC. This positioning of α/β-tubulin onto γTuRC suggests a role for the coiled-coil protein in augmenting γTuRC-mediated MT nucleation. Based on our results, we describe a molecular model for budding yeast γTuRC activation and MT nucleation. |
External links | Nat Struct Mol Biol / PubMed:38609662 / PubMed Central |
Methods | EM (subtomogram averaging) |
Resolution | 6.6 - 9.2 Å |
Structure data | EMDB-18664, PDB-8qv0: EMDB-18665, PDB-8qv2: EMDB-18666, PDB-8qv3: |
Chemicals | ChemComp-GTP: ChemComp-GDP: ChemComp-HOH: |
Source |
|
Keywords | CELL CYCLE / Microtubule nucleation / MTOC / y-tubulin / SPB |