Experiment: 8QQL

Cryo-EM structure of the human inward-rectifier potassium 2.1 channel (Kir2.1) - R312H mutant

ELECTRON MICROSCOPY

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	7ZDZ

Refinement

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	6.451
f_angle_d	0.822
f_chiral_restr	0.049
f_plane_restr	0.006
f_bond_d	0.003

Sample
Human inward-rectifier potassium 2.1 channel (Kir2.1) containing the Andersen-syndrome related mutation R312H

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	FEI VITROBOT MARK IV
Cryogen Name	ETHANE
Sample Vitrification Details	Blotting force 0, blotting time 3s

3D Reconstruction
Reconstruction Method	SINGLE PARTICLE
Number of Particles	146539
Reported Resolution (Å)	6
Resolution Method	FSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry Type	POINT
Point Symmetry	C4

Map-Model Fitting and Refinement
Id	1 (7zdz)
Refinement Space	REAL
Refinement Protocol	FLEXIBLE FIT
Refinement Target
Overall B Value
Fitting Procedure
Details

Data Acquisition
Detector Type	FEI FALCON IV (4k x 4k)
Electron Dose (electrons/Å**2)	40

Imaging Experiment	1
Date of Experiment
Temperature (Kelvin)
Microscope Model	TFS KRIOS
Minimum Defocus (nm)	1200
Maximum Defocus (nm)	2400
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	165000
Calibrated Magnification
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details	Preliminary grid screening was performed manually at a Glacios 2 microscope.

EM Software
Task	Software Package	Version
PARTICLE SELECTION	cryoSPARC	4.2.1
IMAGE ACQUISITION	EPU	2.11
MODEL FITTING	PHENIX	1.20.1_4487
MODEL FITTING	NAMD	1.0
MODEL REFINEMENT	PHENIX	1.20.1_4487
INITIAL EULER ASSIGNMENT	cryoSPARC	4.2.1
FINAL EULER ASSIGNMENT	cryoSPARC	4.2.1
CLASSIFICATION	cryoSPARC	4.2.1
RECONSTRUCTION	cryoSPARC	4.2.1

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
NONE		2787753	A blob picking followed by 2D classification was performed to generate templates for automated template-picking. Initially, 2,787,753 particles were selected after template-picking, which were submitted to three rounds do 2D classification to remove false picks, ice contamination and classes with unclear features.