6NFU

Structure of the KcsA-G77A mutant or the 2,4-ion bound configuration of a K+ channel selectivity filter.

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP		293	PEG400, magnesium acetate, sodium acetate

Crystal Properties
Matthews coefficient	Solvent content
3.94	68.78

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 155.086	α = 90
b = 155.086	β = 90
c = 75.794	γ = 90

Symmetry
Space Group	I 4

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	CCD	MARMOSAIC 325 mm CCD		2015-11-25	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL14-1	0.987	SSRL	BL14-1

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	Net I Over Average Sigma (I)	Redundancy	Number Reflections (All)	Number Reflections (Observed)	Observed Criterion Sigma (F)	Observed Criterion Sigma (I)	B (Isotropic) From Wilson Plot
1	2.09	34.678	99.89	30.38	7.9		53355			35.46

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	2.09	34.678

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	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	1k4c	2.09	34.678	1.34	53330	1208	99.92	0.21	0.2097	0.2236	43.4086

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]

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4006
Nucleic Acid Atoms
Solvent Atoms	305
Heterogen Atoms	45

Software

Software
Software Name	Purpose
HKL-2000	data reduction
HKL-2000	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.