ELECTRON MICROSCOPY

Sample

Undecorated tubulin lattice following polymerisation with GTP (no stabilising ligands).

Specimen Preperation
Sample Aggregation State FILAMENT
Vitrification Instrument LEICA EM GP
Cryogen Name ETHANE
Sample Vitrification Details The sample was incubated on the grid for 10 minutes within the Leica chamber to allow for tubulin polymerisation.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 274847
Reported Resolution (Å) 3.6
Resolution Method FSC 0.143 CUT-OFF
Other Details These are pseudo-particles following the symmetry expansion of ~29,000 particles
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol FLEXIBLE FIT
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details AlphaFoldv2_multimer generated the. model for one tubulin dimer. This was docked into the density within ChimeraX. Molecular dynamics force field-based model fitting was carried out by ISOLDE using unsharpened and deepEMhancer processed density. The model was refined through iterations of ISOLDE and Phenix real_space_refinement softwares.
Data Acquisition
Detector Type GATAN K3 BIOQUANTUM (6k x 4k)
Electron Dose (electrons/Å2) 50.0
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) 600
Maximum Defocus (nm) 2100
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS ?
Imaging Mode BRIGHT FIELD
Specimen Holder Model FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification 81000
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details ?
Imaging Experiment
Task Software Package Version
PARTICLE SELECTION crYOLO v1.7.6.1
IMAGE ACQUISITION EPU ?
CTF CORRECTION CTFFIND 4
MODEL FITTING ISOLDE ?
RECONSTRUCTION RELION 3.1
MODEL REFINEMENT PHENIX ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION ?