3UKM

Crystal structure of the human two pore domain potassium ion channel K2P1 (TWIK-1)

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8	277	20% Peg 400, 150 mM KCl, pH 8.0, VAPOR DIFFUSION, HANGING DROP, temperature 277K

Crystal Properties
Matthews coefficient	Solvent content
4.71	73.87

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 82.08	α = 90
b = 123.171	β = 94.91
c = 119.305	γ = 90

Symmetry
Space Group	P 1 21 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	PIXEL	DECTRIS PILATUS 6M		2011-05-01	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X25	1.1	NSLS	X25

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Sym I (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	3.4	50	99.9	0.057	38.5	12.8	32855	32855		-3

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	3.4	3.46	99.9		2.1	12	1628

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	AB INITIO PHASING	THROUGHOUT	3.4	19.91	29136	1479	89.6	0.273	0.273	0.279	RANDOM	185.7

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]
6.96		16.17	-19.95		12.99

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	18.6
c_scangle_it	10.25
c_scbond_it	7.47
c_mcangle_it	6.79
c_mcbond_it	4.2
c_angle_deg	1.4
c_improper_angle_d	0.84
c_bond_d	0.009
c_bond_d_na
c_bond_d_prot
c_angle_d
c_angle_d_na
c_angle_d_prot
c_angle_deg_na
c_angle_deg_prot
c_dihedral_angle_d_na
c_dihedral_angle_d_prot
c_improper_angle_d_na
c_improper_angle_d_prot

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	7544
Nucleic Acid Atoms
Solvent Atoms	8
Heterogen Atoms	54

Software

Software
Software Name	Purpose
CBASS	data collection
CNS	refinement
HKL-3000	data reduction
HKL-3000	data scaling