6QY3
Segment of the Cas1-Cas2-Csn2-DNA filament complex from the Type II-A CRISPR-Cas system
ELECTRON MICROSCOPY
Sample |
---|
Cas1-Cas2-Csn2-DNA monomer complex |
Sample Components |
Minimal unit of the Cas1-Cas2-Csn2 |
DNA |
Specimen Preparation | |
---|---|
Sample Aggregation State | PARTICLE |
Vitrification Instrument | FEI VITROBOT MARK IV |
Cryogen Name | ETHANE |
Sample Vitrification Details | 15 s wait time, 1 s blot time. |
3D Reconstruction | |
---|---|
Reconstruction Method | SINGLE PARTICLE |
Number of Particles | 66576 |
Reported Resolution (Å) | 9.1 |
Resolution Method | FSC 0.143 CUT-OFF |
Other Details | |
Refinement Type | |
Symmetry Type | POINT |
Point Symmetry | C1 |
Map-Model Fitting and Refinement | |||||
---|---|---|---|---|---|
Id | 1 (6QXF, 6QXF, 6XQF, 6XQF, 6XQF) | ||||
Refinement Space | REAL | ||||
Refinement Protocol | FLEXIBLE FIT | ||||
Refinement Target | Correlation coefficient and visual inspection | ||||
Overall B Value | |||||
Fitting Procedure | |||||
Details | Rigid-body refinement in PHENIX of the higher resolution models, only the idealised linear DNA was subjected to jelly-body refinement in Refmac |
Data Acquisition | |||||||||
---|---|---|---|---|---|---|---|---|---|
Detector Type | FEI FALCON III (4k x 4k) | ||||||||
Electron Dose (electrons/Å**2) | 92.8 |
Imaging Experiment | 1 |
---|---|
Date of Experiment | |
Temperature (Kelvin) | |
Microscope Model | FEI TITAN KRIOS |
Minimum Defocus (nm) | 1300 |
Maximum Defocus (nm) | 2800 |
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 | 75000 |
Calibrated Magnification | 129032 |
Source | FIELD EMISSION GUN |
Acceleration Voltage (kV) | 300 |
Imaging Details |
EM Software | ||
---|---|---|
Task | Software Package | Version |
IMAGE ACQUISITION | EPU | |
CTF CORRECTION | Gctf | |
MODEL FITTING | UCSF Chimera | |
MODEL FITTING | Coot | |
MODEL REFINEMENT | Coot | |
MODEL REFINEMENT | REFMAC | |
MODEL REFINEMENT | PHENIX | |
INITIAL EULER ASSIGNMENT | RELION | 3.0 |
FINAL EULER ASSIGNMENT | RELION | 3.0 |
CLASSIFICATION | RELION | 3.0 |
RECONSTRUCTION | RELION | 3.0 |
Image Processing | ||||
---|---|---|---|---|
CTF Correction Type | CTF Correction Details | Number of Particles Selected | Particle Selection Details | |
PHASE FLIPPING AND AMPLITUDE CORRECTION | 349809 | Reproductions of an initial ab initio generated 3D reconstruction were used as templates for auto picking. |