ELECTRON MICROSCOPY

Sample

Cryo-EM structure of a 2:1 ALK:ALKAL2 complex obtained after re-processing of EMPIAR-10930 data

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument FEI VITROBOT MARK IV
Cryogen Name ETHANE
Sample Vitrification Details QUANTIFOIL R1.2/1/3 gold 300 mesh grids without glow-discharge, blotting time 3 sec., blotting force -5.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 142986
Reported Resolution (Å) 3.2
Resolution Method FSC 0.143 CUT-OFF
Other Details Final 3D refinement was performed in Relion v5 with enabled Blush Regularization.
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol OTHER
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details Rigid-body fitting in Chimera was followed by manual building in Coot and refinement using Phenix real-space refine and Refmac-Servalcat.
Data Acquisition
Detector Type GATAN K3 (6k x 4k)
Electron Dose (electrons/Å2) 81
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) 500
Maximum Defocus (nm) 1500
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 105000
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details SerialEM coma-free alignment
Imaging Experiment
Task Software Package Version
PARTICLE SELECTION cryoSPARC 3.3.1
CTF CORRECTION cryoSPARC 3.3.1
MODEL FITTING UCSF Chimera ?
INITIAL EULER ASSIGNMENT cryoSPARC 4.5
FINAL EULER ASSIGNMENT cryoSPARC 4.5
CLASSIFICATION cryoSPARC 4.5
RECONSTRUCTION RELION 5
MODEL REFINEMENT PHENIX 1.19.2-4158
MODEL REFINEMENT REFMAC ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION ?