3JCF

Cryo-EM structure of the magnesium channel CorA in the closed symmetric magnesium-bound state

ELECTRON MICROSCOPY

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Sample
CorA from Thermotoga maritima in the presence of magnesium

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	LEICA EM GP
Cryogen Name	ETHANE
Sample Vitrification Details	Grids were blotted at 4 degrees Celsius for 7 seconds after a 10-second pre-blotting period, then plunge-frozen in liquid ethane.

3D Reconstruction
Reconstruction Method	SINGLE PARTICLE
Number of Particles	46206
Reported Resolution (Å)	3.8
Resolution Method	FSC 0.143 CUT-OFF
Other Details	Final map was calculated from one dataset. (Single particle details: The particles were selected using an automatic selection program. 3D classification, 3D refinement, and postprocessing were done using RELION 1.3.) (Single particle--Applied symmetry: C5)
Refinement Type
Symmetry Type	POINT
Point Symmetry	C5

Map-Model Fitting and Refinement
Id	1 (4I0U)
Refinement Space	REAL
Refinement Protocol
Refinement Target
Overall B Value
Fitting Procedure
Details

Data Acquisition
Detector Type	GATAN K2 QUANTUM (4k x 4k)
Electron Dose (electrons/Å**2)	40

Imaging Experiment	1
Date of Experiment	2014-08-21
Temperature (Kelvin)	79.7
Microscope Model	FEI TITAN KRIOS
Minimum Defocus (nm)	860
Maximum Defocus (nm)	2500
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	105000
Calibrated Magnification	105000
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details	Parallel beam illumination

EM Software
Task	Software Package	Version
MODEL FITTING	Coot
MODEL FITTING	PHENIX
MODEL FITTING	UCSF Chimera
RECONSTRUCTION	RELION

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
	CTF parameters obtained from whole micrograph