ELECTRON MICROSCOPY

Sample

human BK channel reconstituted into liposomes

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument FEI VITROBOT MARK IV
Cryogen Name ETHANE
Sample Vitrification Details BK proteoliposomes were applied onto a glow-discharged perforated carbon grid (CFlat R2/2, EMS), and incubated for 5-10 min In an FEI Vitrobot Mark IV (FEI). After incubation, the sample was blotted from the side and buffer containing 10 mM HEPES, pH 7.3, 75 mM KCl, and 1 mM EDTA was applied onto the TEM grid to further swell proteoliposomes. Then grids were blotted for 7 s with force 0 and fast frozen in liquid ethane cooled by liquid nitrogen.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 122456
Reported Resolution (Å) 3.5
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 ?
Overall B Value ?
Fitting Procedure ?
Details ?
Data Acquisition
Detector Type GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å2) 60
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) 852
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 130000
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details The Coma free alignment was performed using Auto-CTF software from FEI.
Imaging Experiment
Task Software Package Version
PARTICLE SELECTION RELION 2.1
PARTICLE SELECTION MATLAB R2018a
IMAGE ACQUISITION Leginon 3.3
CTF CORRECTION CTFFIND 4
CTF CORRECTION Gctf ?
INITIAL EULER ASSIGNMENT RELION 2.1
FINAL EULER ASSIGNMENT RELION 2.1
CLASSIFICATION RELION 2.1
RECONSTRUCTION RELION 2.1
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION CTF full correction was performed following RELION 3D reconstruction