6N4U

MicroED structure of Proteinase K at 2.75A resolution from a single milled crystal.

ELECTRON CRYSTALLOGRAPHY

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	6CL7

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 67.46	α = 90
b = 67.46	β = 90
c = 106.67	γ = 90

Symmetry
Space Group	P 43 21 2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work (Depositor)	R-Free (Depositor)	R-Free Selection Details	Mean Isotropic B
ELECTRON CRYSTALLOGRAPHY	MOLECULAR REPLACEMENT	FREE R-VALUE	6CL7	2.75	43.546	1.34	6008	383	87.76	0.2393	0.2377	0.2626	From 5I9S

Temperature Factor Modeling
Anisotropic B[1][1]	Anisotropic B[1][2]	Anisotropic B[1][3]	Anisotropic B[2][2]	Anisotropic B[2][3]	Anisotropic B[3][3]

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	14.908
f_angle_d	0.697
f_chiral_restr	0.044
f_bond_d	0.005
f_plane_restr	0.004

Software

Software
Software Name	Purpose
PHENIX	refinement

Sample
Proteinase K

Specimen Preparation
Sample Aggregation State	3D ARRAY
Vitrification Instrument	FEI VITROBOT MARK IV
Cryogen Name	ETHANE
Sample Vitrification Details

3D Reconstruction
Reconstruction Method	CRYSTALLOGRAPHY
Number of Particles
Reported Resolution (Å)	2.75
Resolution Method	DIFFRACTION PATTERN/LAYERLINES
Other Details
Refinement Type
Symmetry Type	3D CRYSTAL
Space Group Name
Length a	67.46
Length b	67.46
Length c	67.46
Angle Alpha	90
Angle Beta	90
Angle Gamma	90

Map-Model Fitting and Refinement
Id	1 (5I9S)
Refinement Space	RECIPROCAL
Refinement Protocol	RIGID BODY FIT
Refinement Target	R
Overall B Value	21.1
Fitting Procedure
Details

Data Acquisition
Detector Type	FEI CETA (4k x 4k)
Electron Dose (electrons/Å**2)	0.04

Imaging Experiment	1
Date of Experiment
Temperature (Kelvin)
Microscope Model	FEI TALOS ARCTICA
Minimum Defocus (nm)
Maximum Defocus (nm)
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS
Imaging Mode	DIFFRACTION
Specimen Holder Model	FEI TITAN KRIOS AUTOGRID HOLDER
Nominal Magnification
Calibrated Magnification
Source	FIELD EMISSION GUN
Acceleration Voltage (kV)	200
Imaging Details

EM Software
Task	Software Package	Version
MODEL FITTING	PHENIX	1.14
MOLECULAR REPLACEMENT	PHENIX	2.8.2
MODEL REFINEMENT	PHENIX	1.14

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
NONE	NONE

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.