Table 1 Cryo-EM data collection, refinement, and validation statistics.

Data collection and processing information for the EML4-NTD–bound 13-protofilament HeLa cell tubulin microtubule dataset and refinement statistics for the HeLa cell tubulin dimer model asymmetric unit built into the symmetrized electron density map.

(EMD-0331, PDB ID: 6I2I)
Data collection and processing
Pixel size (Å)1.37
Symmetry imposed*Pseudo-helical
Number of micrographs1967
Initial particle images (no.)44,946
Final particle images (no.)19,542
Symmetrized map resolution (Å)3.58
FSC thresholdIndependent half-map FSC 0.143
Map resolution range (Å)3.5–4.3
Initial models used6DPU, 5SYF
Refinement resolution (Å)3.7
Map local sharpening B-factor (Å2)−90
Model composition
Nonhydrogen atoms41,058
Protein residues5256
rms deviations§
Bond lengths (Å)0.01
Bond angles (°)1.20
MolProbity score1.91
Poor rotamers (%)0.5
Ramachandran plot
Favored (%)92.73
Allowed (%)7.27
Outliers (%)0

*Microtubules exhibit pseudo-helical symmetry due to a symmetry break at the seam. Thirteen-fold pseudo-helical symmetry was applied to the 13 protofilament microtubule reconstructions.

†The resolution value at the gold-standard Fourier shell correlation (FSC) 0.143 criterion between independently refined half-maps is shown for the central 15% of the reconstruction along the helical axis (isolated with a soft mask).

‡Average FSC between the model and the symmetrized electron density map of the asymmetric unit (calculated around model atoms only).

§Root mean square (rms) deviations of bond lengths or angles in the model.

‖As defined by the MolProbity validation server (59).