Fig. 2: γ-TuRC assembly starts from a GCP6-stabilized 6-spoke intermediate.
From: Modular assembly of the principal microtubule nucleator γ-TuRC
a Molecular architecture of the 6-spoke assembly. Numbering of spokes according to the full γ-TuRC and coloring of the components as indicated. Substoichiometry of the γ-TuSC(5,6) and γ-TuSC(13,14) units in this reconstruction is indicated by grey coloring in the schematic representation. b Atomic model (PDB 6X0U) superposed to the segmented density of lumenal bridge module 1. The lumenal bridge components are colored as indicated. Zoom as indicated in panel (a). c Zoom on the MZT1-GCP5 module. Atomic model of the MZT1-GCP5 module (PDB 6L81) superposed to the α-helical bundle on the outer surface of the 6-spoke assembly. d The MZT1-GCP5 module binds to the outer surface of GCP3(8), while MZT1-GCP3(8) remains available to form the first module of the lumenal bridge. e Atomic model of the γ-TuRC including newly built segments of the GCP5 and GCP6 N-terminal regions. Zoom focusing on the interaction of the GCP6-NTE with both copies of GCP4, GCP5, and the lumenal bridge components. Interactions are indicated with asterisks. Coloring as in (a).
