6PKT

MicroED structure of proteinase K from merging low-dose, platinum pre-coated lamellae at 1.85A resolution (LDPT)

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 = 67.28	α = 90
b = 67.28	β = 90
c = 106.68	γ = 90

Symmetry
Space Group	P 43 21 2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	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		THROUGHOUT	1.85	32.083	1.34	19710	2366	90.75	0.1898	0.1873	0.225	copied from 6cl7

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	3.436
f_angle_d	1.336
f_chiral_restr	0.076
f_bond_d	0.015
f_plane_restr	0.008

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)	1.85
Resolution Method	DIFFRACTION PATTERN/LAYERLINES
Other Details
Refinement Type
Symmetry Type	3D CRYSTAL
Space Group Name
Length a	67.3
Length b	67.3
Length c	67.3
Angle Alpha	90
Angle Beta	90
Angle Gamma	90

Map-Model Fitting and Refinement
Id	1 (6CL7)
Refinement Space	RECIPROCAL
Refinement Protocol	OTHER
Refinement Target
Overall B Value	24
Fitting Procedure
Details

Data Acquisition
Detector Type	FEI CETA (4k x 4k)
Electron Dose (electrons/Å**2)	0.03

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	1.15
MOLECULAR REPLACEMENT	PHENIX	2.8.2
RECONSTRUCTION	PHENIX	1.15.2
MODEL REFINEMENT	PHENIX	1.15

Image Processing
CTF Correction Type	CTF Correction Details	Number of Particles Selected	Particle Selection Details
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.