7QJB

Structure of recombinant human gamma-Tubulin Ring Complex 12-spoked assembly intermediate (spokes 3-14, homogeneous dataset)

This is a non-PDB format compatible entry.

Summary for 7QJB

• Entry DOI: 10.2210/pdb7qjb/pdb
• EMDB information: 14016
• Descriptor: Tubulin gamma-1 chain, actin, cytoplasmic 1, Gamma-tubulin complex component 3, ... (9 entities in total)
• Functional Keywords: assembly, intermediate, complex, cytosolic protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 35
• Total formula weight: 2626345.36

Authors

Zupa, E.,Pfeffer, S. (deposition date: 2021-12-16, release date: 2022-01-26, Last modification date: 2024-07-17)

Primary citation

Wurtz, M.,Zupa, E.,Atorino, E.S.,Neuner, A.,Bohler, A.,Rahadian, A.S.,Vermeulen, B.J.A.,Tonon, G.,Eustermann, S.,Schiebel, E.,Pfeffer, S.
Modular assembly of the principal microtubule nucleator gamma-TuRC.
Nat Commun, 13:473-473, 2022

PubMed Abstract: The gamma-tubulin ring complex (γ-TuRC) is the principal microtubule nucleation template in vertebrates. Recent cryo-EM reconstructions visualized the intricate quaternary structure of the γ-TuRC, containing more than thirty subunits, raising fundamental questions about γ-TuRC assembly and the role of actin as an integral part of the complex. Here, we reveal the structural mechanism underlying modular γ-TuRC assembly and identify a functional role of actin in microtubule nucleation. During γ-TuRC assembly, a GCP6-stabilized core comprising GCP2-3-4-5-4-6 is expanded by stepwise recruitment, selective stabilization and conformational locking of four pre-formed GCP2-GCP3 units. Formation of the lumenal bridge specifies incorporation of the terminal GCP2-GCP3 unit and thereby leads to closure of the γ-TuRC ring in a left-handed spiral configuration. Actin incorporation into the complex is not relevant for γ-TuRC assembly and structural integrity, but determines γ-TuRC geometry and is required for efficient microtubule nucleation and mitotic chromosome alignment in vivo.

PubMed: 35078983
DOI: 10.1038/s41467-022-28079-0

Experimental method

ELECTRON MICROSCOPY (9.2 Å)