3J8A

Structure of the F-actin-tropomyosin complex

ELECTRON MICROSCOPY

Refinement

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	14.737
f_angle_d	1.097
f_chiral_restr	0.04
f_plane_restr	0.005
f_bond_d	0.004

Sample
F-actin-tropomyosin complex
Sample Components
F-actin (alpha)
tropomyosin (alpha)

Specimen Preparation
Sample Aggregation State	FILAMENT
Vitrification Instrument	GATAN CRYOPLUNGE 3
Cryogen Name	ETHANE
Sample Vitrification Details	Sample was applied to grid, incubated for 10 seconds, and manually blotted for 3 seconds from the backside with filter paper before plunging into liqu ...	Sample was applied to grid, incubated for 10 seconds, and manually blotted for 3 seconds from the backside with filter paper before plunging into liquid ethane (GATAN CRYOPLUNGE 3)

3D Reconstruction
Reconstruction Method	HELICAL
Number of Particles
Reported Resolution (Å)	3.7
Resolution Method	FSC 0.5 CUT-OFF
Other Details	The tropomyosin map filtered to 6.5 Angstrom was merged with the final F-actin map (3.7 Angstrom) to obtain a map of the entire F-actin tropomyosin co ...	The tropomyosin map filtered to 6.5 Angstrom was merged with the final F-actin map (3.7 Angstrom) to obtain a map of the entire F-actin tropomyosin complex. Coordinates must be shifted by (0.123 -0.381 0.273) to match coordinates to fibre diffraction standards (filament axis = z axis passing through x=0 and y=0).
Refinement Type
Symmetry Type	HELICAL
Axial Symmetry	C1
Axial Rise	27.5
Angular Rotation	166.4

Map-Model Fitting and Refinement
Id	1 (4A7N, 4A7N, 4A7N, 4A7N, 4A7N)	2
Refinement Space		REAL
Refinement Protocol	FLEXIBLE FIT	FLEXIBLE FIT
Refinement Target	R-factor	cross-correlation
Overall B Value	55.4
Fitting Procedure
Details	METHOD--maximum likelihood, flexible fitting	METHOD--flexible fitting

Data Acquisition
Detector Type	FEI FALCON II (4k x 4k)
Electron Dose (electrons/Å**2)	14.6

Imaging Experiment	1
Date of Experiment	2013-10-17
Temperature (Kelvin)
Microscope Model	FEI TITAN KRIOS
Minimum Defocus (nm)	800
Maximum Defocus (nm)	2600
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS
Imaging Mode	BRIGHT FIELD
Specimen Holder Model	FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification	59000
Calibrated Magnification
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details	Cs-corrected microscope

EM Software
Task	Software Package	Version
MODEL FITTING	Coot
MODEL FITTING	DireX
MODEL FITTING	PHENIX
RECONSTRUCTION	SPARX

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

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 R01GM157729.