Cryo-electron Tomography and All-atom Molecular Dynamics Simulations Reveal a Novel Kinase Conformational Switch in Bacterial Chemotaxis Signaling
ELECTRON MICROSCOPY
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 1QU7 | |
| Sample |
|---|
| CheA2-trimer core complex |
| Sample Components |
| Chemotaxis protein CheA |
| Chemotaxis protein CheW |
| Methyl-accepting chemotaxis protein II |
| Specimen Preparation | |
|---|---|
| Sample Aggregation State | PARTICLE |
| Vitrification Instrument | HOMEMADE PLUNGER |
| Cryogen Name | ETHANE |
| Sample Vitrification Details | Single-sided blotting (to avoid disruption of the monolayer) before plunging into liquid ethane |
| 3D Reconstruction | |
|---|---|
| Reconstruction Method | TOMOGRAPHY |
| Number of Particles | 4000 |
| Reported Resolution (Å) | 12.7 |
| Resolution Method | FSC 0.143 CUT-OFF |
| Other Details | Gold-standard refinement |
| Refinement Type | HALF-MAPS REFINED INDEPENDENTLY |
| Symmetry Type | 2D CRYSTAL |
| Point Symmetry | C2 |
| Map-Model Fitting and Refinement | |||||
|---|---|---|---|---|---|
| Id | 1 (1QU7) | ||||
| Refinement Space | REAL | ||||
| Refinement Protocol | FLEXIBLE FIT | ||||
| Refinement Target | |||||
| Overall B Value | |||||
| Fitting Procedure | |||||
| Details | REFINEMENT PROTOCOL--FLEXIBLE | ||||
| Data Acquisition | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Detector Type | GATAN ULTRASCAN 4000 (4k x 4k) | ||||||||
| Electron Dose (electrons/Å**2) | 60 | ||||||||
| Imaging Experiment | 1 |
|---|---|
| Date of Experiment | 2009-01-07 |
| Temperature (Kelvin) | |
| Microscope Model | FEI POLARA 300 |
| Minimum Defocus (nm) | 4000 |
| Maximum Defocus (nm) | 8000 |
| Minimum Tilt Angle (degrees) | -70 |
| Maximum Tilt Angle (degrees) | 70 |
| Nominal CS | 2 |
| Imaging Mode | BRIGHT FIELD |
| Specimen Holder Model | OTHER |
| Nominal Magnification | 39000 |
| Calibrated Magnification | 49834 |
| Source | FIELD EMISSION GUN |
| Acceleration Voltage (kV) | 200 |
| Imaging Details |
| Image Processing | ||||
|---|---|---|---|---|
| CTF Correction Type | CTF Correction Details | Number of Particles Selected | Particle Selection Details | |
| TomoCTF (strip-based periodogram) | ||||
