7NO2

Structure of the mature RSV CA lattice: hexamer derived from tubes (C2-symmetric)

ELECTRON MICROSCOPY

Sample
Rous sarcoma virus - Prague C

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	FEI VITROBOT MARK IV
Cryogen Name	ETHANE
Sample Vitrification Details	2.5 seconds blotting time

3D Reconstruction
Reconstruction Method	SUBTOMOGRAM AVERAGING
Number of Particles	40962
Reported Resolution (Å)	4.3
Resolution Method	FSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry Type	POINT
Point Symmetry	C2

Map-Model Fitting and Refinement
Id	1 (3TIR)
Refinement Space	REAL
Refinement Protocol	AB INITIO MODEL
Refinement Target	Correlation coefficient
Overall B Value
Fitting Procedure
Details	Three copies of CA monomer were rigid body-fitted into the EM density to accommodate the 3 symmetry independent CA copies. The fit was further refined ...	Three copies of CA monomer were rigid body-fitted into the EM density to accommodate the 3 symmetry independent CA copies. The fit was further refined in Coot. The symmetry independent copies were expanded according to the C2 symmetry, and an additional ring of CTDs adjacent to the CA hexamer was added to account for the continuous lattice during the refinement. The model was refined by iterating between automatic real space refinement in Phenix and manual model inspection/editing in Coot.

Data Acquisition
Detector Type	GATAN K2 QUANTUM (4k x 4k)
Electron Dose (electrons/Å**2)	3.5

Imaging Experiment	1
Date of Experiment
Temperature (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	105000
Calibrated Magnification
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details	Areas of interest for high-resolution data collection were identified in low magnification montages. Prior to tomogram acquisition, gain references were acquired and the filter was fully tuned. Microscope tuning was performed using the FEI AutoCTF software. The ilumination mode used during acquisition was nanoprobe.

EM Software
Task	Software Package	Version
VOLUME SELECTION	MATLAB	R2018b
VOLUME SELECTION	IMOD	4.9
VOLUME SELECTION	Dynamo	1.1.333
IMAGE ACQUISITION	SerialEM
IMAGE ACQUISITION	DigitalMicrograph
CTF CORRECTION	CTFFIND	4.1.10
CTF CORRECTION	IMOD	4.9
CTF CORRECTION	NOVACTF
MODEL FITTING	UCSF Chimera	1.13.1
MODEL FITTING	Coot	0.8.9.1
FINAL EULER ASSIGNMENT	Dynamo	1.1.333
CLASSIFICATION	MATLAB	R2018b
RECONSTRUCTION	Dynamo	1.1.333
RECONSTRUCTION	AV3
MODEL REFINEMENT	PHENIX	1.18
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	CTF-correction was initially performed using ctfphaseflip in IMOD and NovaCTF in the final steps

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM133198.