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. | ||
