6QXF

Cas1-Cas2-Csn2-DNA complex from the Type II-A CRISPR-Cas system


ELECTRON MICROSCOPY

Starting Model(s)

Initial Refinement Model(s)
TypeSourceAccession CodeDetails
experimental modelPDB 3V7F 
experimental modelPDB 5XVN 
Sample
Cas1-Cas2-Csn2-DNA monomer complex
Sample Components
Cas1-Cas2-Csn2
DNA
Specimen Preparation
Sample Aggregation StatePARTICLE
Vitrification InstrumentFEI VITROBOT MARK IV
Cryogen NameETHANE
Sample Vitrification Details15 s wait time, 1 s blot time.
3D Reconstruction
Reconstruction MethodSINGLE PARTICLE
Number of Particles306470
Reported Resolution (Å)3.6
Resolution MethodFSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry TypePOINT
Point SymmetryC1
Map-Model Fitting and Refinement
Id1 (3V7F, 5XVN, 5XVN, 5XVN)
Refinement SpaceREAL
Refinement ProtocolOTHER
Refinement TargetCorrelation coefficient and visual inspection
Overall B Value
Fitting Procedure
DetailsRounds of manual fitting in Coot, jelly-body refinement in REFMAC and real-space refinement in PHENIX
Data Acquisition
Detector TypeFEI FALCON III (4k x 4k)
Electron Dose (electrons/Å**2)92.8
Imaging Experiment1
Date of Experiment
Temperature (Kelvin)
Microscope ModelFEI TITAN KRIOS
Minimum Defocus (nm)1300
Maximum Defocus (nm)2800
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS2.7
Imaging ModeBRIGHT FIELD
Specimen Holder ModelFEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification75000
Calibrated Magnification129032
SourceFIELD EMISSION GUN
Acceleration Voltage (kV)300
Imaging Details
EM Software
TaskSoftware PackageVersion
IMAGE ACQUISITIONEPU
CTF CORRECTIONGctf
MODEL FITTINGUCSF Chimera
MODEL FITTINGCoot
INITIAL EULER ASSIGNMENTRELION3.0
FINAL EULER ASSIGNMENTRELION3.0
CLASSIFICATIONRELION3.0
RECONSTRUCTIONRELION3.0
MODEL REFINEMENTCoot
MODEL REFINEMENTREFMAC
MODEL REFINEMENTPHENIX
Image Processing
CTF Correction TypeCTF Correction DetailsNumber of Particles SelectedParticle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION853391Reproductions of an initial ab initio generated 3D reconstruction were used as templates for auto picking