8VRD

Rigid body fitted model for free recombinant gamma tubulin ring complex.

Summary for 8VRD

• Entry DOI: 10.2210/pdb8vrd/pdb
• EMDB information: 43481
• Descriptor: Gamma-tubulin complex component 3, TUBGCP6 protein, Mitotic-spindle organizing protein 1, ... (8 entities in total)
• Functional Keywords: complex, cytosolic protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 34
• Total formula weight: 2807021.61

Authors

Aher, A.,Urnavicius, L.,Kapoor, T.M. (deposition date: 2024-01-21, release date: 2024-03-27, Last modification date: 2024-10-09)

Primary citation

Aher, A.,Urnavicius, L.,Xue, A.,Neselu, K.,Kapoor, T.M.
Structure of the gamma-tubulin ring complex-capped microtubule.
Nat.Struct.Mol.Biol., 31:1124-1133, 2024

PubMed Abstract: Microtubules are composed of α-tubulin and β-tubulin dimers positioned head-to-tail to form protofilaments that associate laterally in varying numbers. It is not known how cellular microtubules assemble with the canonical 13-protofilament architecture, resulting in micrometer-scale α/β-tubulin tracks for intracellular transport that align with, rather than spiral along, the long axis of the filament. We report that the human ~2.3 MDa γ-tubulin ring complex (γ-TuRC), an essential regulator of microtubule formation that contains 14 γ-tubulins, selectively nucleates 13-protofilament microtubules. Cryogenic electron microscopy reconstructions of γ-TuRC-capped microtubule minus ends reveal the extensive intra-domain and inter-domain motions of γ-TuRC subunits that accommodate luminal bridge components and establish lateral and longitudinal interactions between γ-tubulins and α-tubulins. Our structures suggest that γ-TuRC, an inefficient nucleation template owing to its splayed conformation, can transform into a compacted cap at the microtubule minus end and set the lattice architecture of cellular microtubules.

PubMed: 38609661
DOI: 10.1038/s41594-024-01264-z

Experimental method

ELECTRON MICROSCOPY (7 Å)