5I08

Prefusion structure of a human coronavirus spike protein


ELECTRON MICROSCOPY
Sample
HKU1 spike with attached foldon domain and mutated furin-cleavage site
Specimen Preparation
Sample Aggregation StatePARTICLE
Vitrification InstrumentHOMEMADE PLUNGER
Cryogen NameETHANE
Sample Vitrification Details3 uL sample was applied to grid, blotted, and plunged into liquid ethane.
Staining TypeNEGATIVE
Staining Materialuranyl formate
Staining Details3 uL sample was applied to grid for 30 seconds and then blotted. Grids were stained with 3 uL 1% uranyl formate for 60 seconds followed by blotting.
3D Reconstruction
Reconstruction MethodSINGLE PARTICLE
Number of Particles31435
Reported Resolution (Å)4.04
Resolution MethodFSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry TypePOINT
Point SymmetryC3
Map-Model Fitting and Refinement
Id1
Refinement SpaceREAL
Refinement ProtocolAB INITIO MODEL
Refinement TargetEMRinger
Overall B Value117
Fitting Procedure
DetailsModel building and refinement were conducted using a combination of software programs.
Data Acquisition
Detector TypeGATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å**2)57
Imaging Experiment1
Date of Experiment
Temperature (Kelvin)
Microscope ModelFEI TITAN KRIOS
Minimum Defocus (nm)1000
Maximum Defocus (nm)3500
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS
Imaging ModeBRIGHT FIELD
Specimen Holder ModelFEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification22500
Calibrated Magnification22500
SourceFIELD EMISSION GUN
Acceleration Voltage (kV)300
Imaging Details
EM Software
TaskSoftware PackageVersion
PARTICLE SELECTIONDoG Picker
PARTICLE SELECTIONFindEM
IMAGE ACQUISITIONLeginon
CTF CORRECTIONCTFFIND3
MODEL FITTINGMODELLER
MODEL FITTINGRosetta2015.19
MODEL FITTINGCoot0.8.2
INITIAL EULER ASSIGNMENTRELION1.3
FINAL EULER ASSIGNMENTRELION1.4b1
CLASSIFICATIONIMAGIC
RECONSTRUCTIONRELION1.4b1
MODEL REFINEMENTRosetta2015.19
Image Processing
CTF Correction TypeCTF Correction DetailsNumber of Particles SelectedParticle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION391642188 particles were selected from a subset of the data using DoG Picker. These particles were used to generate a 3D model from which back projections were derived. Back projection images were used as templates for picking particles from the entire dataset using FindEM.