5NL2
cryo-EM structure of the mTMEM16A ion channel at 6.6 A resolution.
ELECTRON MICROSCOPY
Starting Model(s)
| Initial Refinement Model(s) | |||
|---|---|---|---|
| Type | Source | Accession Code | Details |
| experimental model | PDB | 4WIT | |
Refinement
| RMS Deviations | |
|---|---|
| Key | Refinement Restraint Deviation |
| f_dihedral_angle_d | 4.269 |
| f_angle_d | 0.632 |
| f_chiral_restr | 0.042 |
| f_plane_restr | 0.005 |
| f_bond_d | 0.004 |
| Sample |
|---|
| mTMEM16A |
| Specimen Preparation | |
|---|---|
| Sample Aggregation State | PARTICLE |
| Vitrification Instrument | FEI VITROBOT MARK IV |
| Cryogen Name | ETHANE |
| Sample Vitrification Details | 2.5 ul sample volume 1-5 sec blotting time |
| 3D Reconstruction | |
|---|---|
| Reconstruction Method | SINGLE PARTICLE |
| Number of Particles | 213243 |
| Reported Resolution (Å) | 6.6 |
| Resolution Method | FSC 0.143 CUT-OFF |
| Other Details | |
| Refinement Type | |
| Symmetry Type | POINT |
| Point Symmetry | C2 |
| Map-Model Fitting and Refinement | |||||
|---|---|---|---|---|---|
| Id | 1 (4WIT) | ||||
| Refinement Space | |||||
| Refinement Protocol | RIGID BODY FIT | ||||
| Refinement Target | |||||
| Overall B Value | |||||
| Fitting Procedure | |||||
| Details | |||||
| Data Acquisition | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| Detector Type | GATAN K2 SUMMIT (4k x 4k) | ||||||||
| Electron Dose (electrons/Å**2) | 80 | ||||||||
| Imaging Experiment | 1 |
|---|---|
| Date of Experiment | |
| Temperature (Kelvin) | |
| Microscope Model | FEI TITAN KRIOS |
| Minimum Defocus (nm) | 500 |
| Maximum Defocus (nm) | 3800 |
| 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 | 37037 |
| Calibrated Magnification | 37037 |
| Source | FIELD EMISSION GUN |
| Acceleration Voltage (kV) | 300 |
| Imaging Details |
| EM Software | ||
|---|---|---|
| Task | Software Package | Version |
| PARTICLE SELECTION | RELION | 2 |
| IMAGE ACQUISITION | SerialEM | |
| CTF CORRECTION | CTFFIND | 4.1.5 |
| MODEL FITTING | Coot | |
| MODEL REFINEMENT | PHENIX | |
| INITIAL EULER ASSIGNMENT | RELION | 2 |
| FINAL EULER ASSIGNMENT | RELION | 2 |
| CLASSIFICATION | RELION | 2 |
| RECONSTRUCTION | RELION | 2 |
| Image Processing | ||||
|---|---|---|---|---|
| CTF Correction Type | CTF Correction Details | Number of Particles Selected | Particle Selection Details | |
| PHASE FLIPPING AND AMPLITUDE CORRECTION | The contrast transfer function (CTF) parameters were estimated on the movie frames by ctffind4.1 | 755348 | Images showing a strong drift, higher defocus than -3.8 um or a bad CTF estimation were discarded, resulting in 4,178 images used for further analysis. Image processing was performed using the software package RELION1.4 and at a later stage RELION2.0. Approximately 4,000 particles were manually picked to generate templates for automated particle selection. Following automated picking in RELION, false positives were eliminated manually or through a first round of 2D classification resulting in 755,348 particles. | |
