ELECTRON MICROSCOPY

Sample

Fully-loaded anthrax lethal toxin in its heptameric pre-pore state and PA7LF(2+1B) arrangement

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument GATAN CRYOPLUNGE 3
Cryogen Name ETHANE
Sample Vitrification Details 4 uL sample was applied to grid (with 2 nm additional carbon layer) and incubated for 45 s prior blotting.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 99000
Reported Resolution (Å) 3.8
Resolution Method FSC 0.143 CUT-OFF
Other Details ?
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space ?
Refinement Protocol ?
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details The previously generated PA7LF3-masked model (PDB:6ZXJ) served as starting point and was placed into the density using rigid-body fit in Chimera. From this model, chain H was duplicated and fitted into the density corresponding to the third LF. For the entire model a restrained refinement in phenix was performed. The resulting model was further refined with a combination of phenix and coot. Unresolved regions were deleted and side chain information was removed for less well-resolved regions.
Data Acquisition
Detector Type GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å2) 74.4
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model FEI TITAN KRIOS
Minimum Defocus (nm) ?
Maximum Defocus (nm) ?
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 ?
Imaging Experiment
Task Software Package Version
PARTICLE SELECTION crYOLO ?
IMAGE ACQUISITION EPU 1.10
CTF CORRECTION SPHIRE ?
FINAL EULER ASSIGNMENT SPHIRE ?
CLASSIFICATION SPHIRE ?
RECONSTRUCTION SPHIRE ?
MODEL REFINEMENT PHENIX 1.18.2
MODEL REFINEMENT Coot 0.8.9.1
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION ?