Extended Data Fig. 4: Cryo-EM reconstruction of γ-TuRC-nucleated microtubule protofilament reveals a compacted lattice.
From: Structure of the γ-tubulin ring complex-capped microtubule
(a) Schematic for γ-TuRC-nucleated microtubule used for cryo-EM reconstruction (b, c) Cryo-EM density map for γ-TuRC-nucleated microtubule protofilament showing a view of the ɑ/β-tubulin dimer from the outside (b) and from within the lumen (c) (ɑ-tubulin: lighter green; β-tubulin: darker green). (d-e) Densities (mesh) for the nucleotide bound to ɑ-tubulin (GTP) (d) and β-tubulin (GDP) (e). (f-g) Models for 2 tubulin heterodimers from a γ-TuRC-nucleated microtubule protofilament and a protofilament from GDP-microtubule (PDB ID:6DPV) (f) or GMPCPP-microtubule (PDB ID:6DPU) (g) aligned at the first ɑ-tubulin. Distances between Cɑ atoms for 10 residues across 2 successive ɑ-tubulins were measured and averaged. (h) Four tubulin models rigid-body fitted into γ-TuRC-nucleated microtubule map at position 7 were used to measure distances between Cɑ atoms for 10 residues across two successive ɑ-tubulins.
