7CFS

Cryo-EM strucutre of human acid-sensing ion channel 1a at pH 8.0


ELECTRON MICROSCOPY
Sample
hASIC1a
Specimen Preparation
Sample Aggregation StatePARTICLE
Vitrification InstrumentFEI VITROBOT MARK IV
Cryogen NameETHANE
Sample Vitrification DetailsPurified hASIC1a-DeltaC (3 ul) at a concentration of 2.7 mg/ml was added to the freshly plasma-cleaned holey carbon grid (Quantifol, R1.2/1.3, 300 mes ...Purified hASIC1a-DeltaC (3 ul) at a concentration of 2.7 mg/ml was added to the freshly plasma-cleaned holey carbon grid (Quantifol, R1.2/1.3, 300 mesh, Cu), blotted for 5 s at 100% humidity with a Vitrobot Mark IV (ThermoFisher Scientific) and plunge frozen into liquid ethane cooled by liquid nitrogen.
3D Reconstruction
Reconstruction MethodSINGLE PARTICLE
Number of Particles122890
Reported Resolution (Å)3.56
Resolution MethodFSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry TypePOINT
Map-Model Fitting and Refinement
Id1 (6AVE)
Refinement Space
Refinement ProtocolFLEXIBLE FIT
Refinement Target
Overall B Value
Fitting Procedure
Details
Data Acquisition
Detector TypeGATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å**2)50
Imaging Experiment1
Date of Experiment
Temperature (Kelvin)
Microscope ModelFEI TITAN KRIOS
Minimum Defocus (nm)
Maximum Defocus (nm)
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS
Imaging ModeBRIGHT FIELD
Specimen Holder ModelFEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification
Calibrated Magnification
SourceFIELD EMISSION GUN
Acceleration Voltage (kV)300
Imaging DetailsGrids were transferred to a Titan Krios electron microscope (FEI) operated at 300 kV equipped with a Gatan K2 Summit direct detection camera. Images of hASIC1a was collected using the automated image acquisition software SerialEM in counting mode with 29,000x magnification yielding a pixel size of 1.014 A. The total dose of 50 e-/A2 was fractionated to 40 frames with 0.2 s per frame. Nominal defocus values ranged from -1.8 to -2.5 um. The dataset of hASIC1a included 3,235 micrographs.
EM Software
TaskSoftware PackageVersion
PARTICLE SELECTIONRELION2.1
CTF CORRECTIONGctf
MODEL FITTINGUCSF Chimera
CLASSIFICATIONRELION2.1
RECONSTRUCTIONRELION2.1
MODEL REFINEMENTPHENIX
Image Processing
CTF Correction TypeCTF Correction DetailsNumber of Particles SelectedParticle Selection Details
PHASE FLIPPING AND AMPLITUDE CORRECTION274796