γ-TuRC asymmetry induces local protofilament mismatch at the RanGTP-stimulated microtubule minus end

ABSTRACT: The γ-tubulin ring complex (γ-TuRC) is a structural template for de novo microtubule assembly from α/β-tubulin units. The isolated vertebrate γ-TuRC assumes an asymmetric, open structure deviating from microtubule geometry, suggesting that γ-TuRC closure may underlie regulation of microtubule nucleation. Here, we isolate native γ-TuRC-capped microtubules from Xenopus laevis egg extract nucleated through the RanGTP-induced pathway for spindle assembly and determine their cryo-EM structure. Intriguingly, the microtubule minus end-bound γ-TuRC is only partially closed and consequently, the emanating microtubule is locally misaligned with the γ-TuRC and asymmetric. In the partially closed conformation of the γ-TuRC, the actin-containing lumenal bridge is locally destabilised, suggesting lumena

SUBMITTER: Prof. Elmar Schiebel 

PROVIDER: S-SCDT-10_1038-S44318-024-00087-4 | biostudies-other |

REPOSITORIES: biostudies-other