6T1R

Pseudo-atomic model of a 16-mer assembly of reduced recombinant human alphaA-crystallin (non domain swapped configuration)

ELECTRON MICROSCOPY

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	3N3E

Sample
Reduced recombinant human alphaA-crystallin

Specimen Preparation
Sample Aggregation State	PARTICLE
Vitrification Instrument	HOMEMADE PLUNGER
Cryogen Name	ETHANE
Sample Vitrification Details	Diluted equilibrated specimen was added to glow-discharged (30s) grids. Sample was blotted 30s after sample application and immediately plunged.

3D Reconstruction
Reconstruction Method	SINGLE PARTICLE
Number of Particles	19783
Reported Resolution (Å)	9.8
Resolution Method	FSC 0.143 CUT-OFF
Other Details
Refinement Type
Symmetry Type	POINT
Point Symmetry	D4

Map-Model Fitting and Refinement
Id	1 (3N3E)
Refinement Space
Refinement Protocol	FLEXIBLE FIT
Refinement Target
Overall B Value
Fitting Procedure
Details	Structure created by homology modelling using PDB 3N3E and the N-terminal region (1-60) modelled using I-Tasser. The model was refined by flexible fit ...	Structure created by homology modelling using PDB 3N3E and the N-terminal region (1-60) modelled using I-Tasser. The model was refined by flexible fitting into the EM density map EMD-4894. The N-terminus is modelled only as CA atoms.

Data Acquisition
Detector Type	GATAN K2 SUMMIT (4k x 4k)
Electron Dose (electrons/Å**2)	30

Imaging Experiment	1
Date of Experiment
Temperature (Kelvin)
Microscope Model	FEI TITAN KRIOS
Minimum Defocus (nm)	1200
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	37000
Calibrated Magnification	37037
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	300
Imaging Details

EM Software
Task	Software Package	Version
PARTICLE SELECTION	EMAN2	2.0
IMAGE ACQUISITION	TOM
CTF CORRECTION	Bsoft
MODEL FITTING	Amber	16
RECONSTRUCTION	IMAGIC	5
MODEL REFINEMENT	Amber	16

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
PHASE FLIPPING ONLY		74068	particles were picked manually

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.