Experiment: 6SKO

Cryo-EM Structure of the Fork Protection Complex Bound to CMG at a Replication Fork - conformation 2 MCM CTD:ssDNA

ELECTRON MICROSCOPY

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	5U8S

Sample
Conformation 2 of CMG-Csm3-Tof1-Mrc1-Ctf4 with a fork DNA
Sample Components
CMG-Csm3-Tof1-Mrc1-Ctf4
DNA

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	HOMEMADE PLUNGER
Cryogen Name	ETHANE
Sample Vitrification Details	Three microlitres of sample was applied on a grid and incubated for 15-30 s at 4 degC before manually blotting with filter paper for 10 s and plunge-f ...	Three microlitres of sample was applied on a grid and incubated for 15-30 s at 4 degC before manually blotting with filter paper for 10 s and plunge-freezing in liquid ethane.

3D Reconstruction
Reconstruction Method	SINGLE PARTICLE
Number of Particles	182000
Reported Resolution (Å)	3.4
Resolution Method	FSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry Type	POINT
Point Symmetry	C1

Map-Model Fitting and Refinement
Id	1 (5U8S, 5U8S, 5U8S, 5U8S, 5U8S, 5U8S)
Refinement Space	REAL
Refinement Protocol	OTHER
Refinement Target	FSC 0.5
Overall B Value	20
Fitting Procedure
Details

Data Acquisition
Detector Type	GATAN K2 QUANTUM (4k x 4k)
Electron Dose (electrons/Å**2)	37

Imaging Experiment	1
Date of Experiment
Temperature (Kelvin)
Microscope Model	FEI TITAN KRIOS
Minimum Defocus (nm)	1400
Maximum Defocus (nm)	2600
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

EM Software
Task	Software Package	Version
IMAGE ACQUISITION	EPU	1.9.1
CTF CORRECTION	Gctf	0.50
MODEL FITTING	UCSF Chimera	1.8.1
MODEL FITTING	Coot	0.9-pre
INITIAL EULER ASSIGNMENT	RELION	3.0
FINAL EULER ASSIGNMENT	RELION	3.0
CLASSIFICATION	RELION	3.0
RECONSTRUCTION	RELION	3.0
MODEL REFINEMENT	REFMAC
MODEL REFINEMENT	PHENIX

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION		632000