ELECTRON MICROSCOPY

Sample

Complex of translation initiation factors eIF2 and eIF2B

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument FEI VITROBOT MARK III
Cryogen Name ETHANE
Sample Vitrification Details Blot for 2 seconds before plunging
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 64541
Reported Resolution (Å) 3.93
Resolution Method FSC 0.143 CUT-OFF
Other Details ?
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol FLEXIBLE FIT
Refinement Target correlation coeficient
Overall B Value ?
Fitting Procedure ?
Details Modeller was used to build homology model of S. cerevisiae eIF2B structure based on S. pombe crystal structure. Subunits of the homology model, along with eIF2 alpha domains 1 and 2, were then rigid body fitted into our map using UCSF Chimera. The model then was refined using phenix and manually adjusted in Coot.
Data Acquisition
Detector Type GATAN K2 QUANTUM (4k x 4k)
Electron Dose (electrons/Å2) 40
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) 1500
Maximum Defocus (nm) 4000
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 2.7
Imaging Mode BRIGHT FIELD
Specimen Holder Model FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification ?
Calibrated Magnification 37313
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details Tilt at zero and 35 degrees.
Imaging Experiment
Task Software Package Version
PARTICLE SELECTION RELION 2.01
IMAGE ACQUISITION EPU ?
CTF CORRECTION Gctf ?
MODEL FITTING MODELLER ?
MODEL FITTING UCSF Chimera ?
MODEL FITTING Coot ?
INITIAL EULER ASSIGNMENT RELION 2.1
FINAL EULER ASSIGNMENT RELION 2.1
CLASSIFICATION RELION 2.1
RECONSTRUCTION RELION 2.1
MODEL REFINEMENT PHENIX ?
MODEL FITTING UCSF Chimera ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION CTF determination was performed per micrograph initially. After particle picking and initial reconstruction, per particle CTF determination was performed.