3JC1

Electron cryo-microscopy of the IST1-CHMP1B ESCRT-III copolymer

ELECTRON MICROSCOPY

Sample
IST1-NTD and CHMP1B double-stranded helical filament
Sample Components
IST1
CHMP1B

Specimen Preparation
Sample Aggregation State	FILAMENT
Vitrification Instrument	FEI VITROBOT MARK III
Cryogen Name	ETHANE
Sample Vitrification Details	Deposited 3.5 uL sample, blotted 3-6 seconds (0 mm offset), and plunged into liquid ethane (VITROBOT MARK III).

3D Reconstruction
Reconstruction Method	HELICAL
Number of Particles	188713
Reported Resolution (Å)	4
Resolution Method
Other Details	Modified version of IHRSR algorithms as implemented in SPIDER was used to determine the helical symmetry. 3D reconstructions were performed using RELI ...	Modified version of IHRSR algorithms as implemented in SPIDER was used to determine the helical symmetry. 3D reconstructions were performed using RELION.
Refinement Type
Symmetry Type	HELICAL
Axial Symmetry	C1
Axial Rise	2.96
Angular Rotation	21.06

Map-Model Fitting and Refinement
Id	1 (3FRR)
Refinement Space	REAL
Refinement Protocol
Refinement Target	Molprobity validation, cross-correlation
Overall B Value
Fitting Procedure
Details	DETAILS--IST1 starting model (3FRR) was idealized in Rosetta, then relaxed while the structure was constrained. Iterative loop building was used.

Data Acquisition
Detector Type	KODAK SO-163 FILM
Electron Dose (electrons/Å**2)	20

Imaging Experiment	1	2	3
Date of Experiment	2013-06-01	2013-06-01	2013-06-01
Temperature (Kelvin)
Microscope Model	FEI TITAN KRIOS	FEI TECNAI F20	JEOL 3200FSC
Minimum Defocus (nm)	600	600	600
Maximum Defocus (nm)	3000	3000	3000
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS	2	2	3.4
Imaging Mode	BRIGHT FIELD	BRIGHT FIELD	BRIGHT FIELD
Specimen Holder Model
Nominal Magnification	59000	50000	59000
Calibrated Magnification
Source	FIELD EMISSION GUN	FIELD EMISSION GUN	FIELD EMISSION GUN
Acceleration Voltage (kV)	300	200	300
Imaging Details

EM Software
Task	Software Package	Version
CTF CORRECTION	CTFFIND	3
MODEL FITTING	Coot
MODEL FITTING	MDFF
MODEL FITTING	NAMD
MODEL FITTING	Rosetta
MODEL FITTING	UCSF Chimera
RECONSTRUCTION	EMAN	2
RECONSTRUCTION	IHRSR
RECONSTRUCTION	RELION
RECONSTRUCTION	SPIDER

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
	CTFFIND3

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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.