ELECTRON MICROSCOPY

Sample

Single-particle cryo-EM map of MFSD2A isoform B from zebrafish with a Fab in the inward open ligand 2B conformation at an average resolution of 3.4 A, filtered to local resolution

Specimen Preperation
Sample Aggregation State PARTICLE
Vitrification Instrument LEICA EM GP
Cryogen Name ETHANE
Sample Vitrification Details 400-mesh 1.2/1.3 Cu grids (Quantifoil) were made hydrophilic by glow discharging for two times 60 seconds with a current of 15 mA in a PELCO easiGlow system. The cryo grids were produced using a Leica EM GP (Leica). The chamber was kept at 4 C and 95% humidity (86-91% measured). 3 microliter sample at 3 mg/ml was applied to a glow-discharged holey grid, blotted for 6 s, and plunge frozen into liquid ethane and stored in liquid nitrogen.
3D Reconstruction
Reconstruction Method SINGLE PARTICLE
Number of Particles 76700
Reported Resolution (Å) 3.4
Resolution Method FSC 0.143 CUT-OFF
Other Details ?
Refinement Type
Symmetry Type POINT
Map-Model Fitting and Refinement
ID 1
Refinement Space REAL
Refinement Protocol RIGID BODY FIT
Refinement Target ?
Overall B Value ?
Fitting Procedure ?
Details ?
Data Acquisition
Detector Type GATAN K3 BIOQUANTUM (6k x 4k)
Electron Dose (electrons/Å2) 50
Imaging Experiment
Date of Experiment ?
Temprature (Kelvin)
Microscope Model TFS KRIOS
Minimum Defocus (nm) 500
Maximum Defocus (nm) 1800
Minimum Tilt Angle (degrees) ?
Maximum Tilt Angle (degrees) ?
Nominal CS 0.01
Imaging Mode BRIGHT FIELD
Specimen Holder Model FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification 81000
Calibrated Magnification ?
Source FIELD EMISSION GUN
Acceleration Voltage (kV) 300
Imaging Details Cryo-EM grids were loaded into a 300 keV FEI Titan Krios cryo electron microscope (ThermoFisher Scientific, formerly FEI) at HHMI Janelia Reasearch Campus, Janelia Krios 1, equipped with a Cs corrector, and Gatan energy filter and K3 camera (Gatan Inc.). Movies of 50 frames with 1 e-/A2 per frame (50 e-/A2 total dose) were automatically recorded at a nominal magnification of 81,000x, corresponding to a physical pixel size of 0.844 A/px (superresolution pixel size 0.422 A/px) in CDS mode at a dose rate of 9.5 e-/px/s (~7.5 e-/px/s on the camera through the sample) and a defocus range of -0.5 to -1.8 micrometer using SerialEM. In total, 2,653 and 8,443 movies were collected in two separate imaging sessions, with the first dataset on a 400-mesh copper grid and the second on a 300-mesh UltrAuFoil gold grid.
Imaging Experiment
Task Software Package Version
MODEL FITTING UCSF Chimera ?
IMAGE ACQUISITION SerialEM ?
INITIAL EULER ASSIGNMENT cryoSPARC v3.3.2
FINAL EULER ASSIGNMENT cryoSPARC v3.3.2
CLASSIFICATION cryoSPARC v3.3.2
RECONSTRUCTION cryoSPARC v3.3.2
MODEL FITTING Coot ?
MODEL REFINEMENT Coot ?
MODEL REFINEMENT PHENIX ?
Image Processing
CTF Correction Type CTF Correction Details Number of Particles Selected Particle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION ?