Experiment: 2HG5

Cs+ complex of a K channel with an amide to ester substitution in the selectivity filter

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6.5	295	Crystals of the KcsAester-Fab complex grown in the presence of 300 mM KCl were washed 2X in a similar solution containing 0.3M CsCl, incubated overnight in the presence of 0.3M CsCl and then cryoprotected. 50 mM Magnesium acetate, PEG 400 (20-25%), pH 6.5, VAPOR DIFFUSION, SITTING DROP, temperature 295K

Crystal Properties
Matthews coefficient	Solvent content
4.03	69.46

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 156.597	α = 90
b = 156.597	β = 90
c = 75.706	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	ADSC QUANTUM 315		2005-07-05	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 Merge 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	2.75	100	97	0.087	15.8	3.9		23274

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.75	2.85	98.5		0.434		3.9	2362

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-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	2.75	26.1	23257	1195	96.8	0.239	0.2359	0.271	0.2701	RANDOM	57.9

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]
5.08			5.08		-10.17

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	25.5
c_scangle_it	3.16
c_mcangle_it	2.74
c_scbond_it	2.02
c_mcbond_it	1.56
c_angle_deg	1.4
c_improper_angle_d	0.9
c_bond_d	0.008

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4056
Nucleic Acid Atoms
Solvent Atoms	29
Heterogen Atoms	25

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
CNS	refinement
PDB_EXTRACT	data extraction
MOLREP	phasing