2QC1

Crystal structure of the extracellular domain of the nicotinic acetylcholine receptor 1 subunit bound to alpha-bungarotoxin at 1.9 A resolution

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	2BYP	pdb entry 2BYP

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6	277	0.1M Na citrate, 18% 2-propanol, 8% PEG 4000, pH 6.0, VAPOR DIFFUSION, HANGING DROP, temperature 277K

Crystal Properties
Matthews coefficient	Solvent content
2.64	53.48

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 42.498	α = 90
b = 85.68	β = 90
c = 95.15	γ = 90

Symmetry
Space Group	P 21 21 21

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 4		2006-02-17	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ALS BEAMLINE 8.2.1	1.0	ALS	8.2.1

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	1.94	50	87.1	0.09	20	16	26445	23030	2	2	7.3

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.94	2.06	67.4		41	4	5	2601

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	pdb entry 2BYP	1.94	41.59	2	26445	23030	2255	9.8	0.214	0.233	random	30.8

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]
-0.424			4.576		-4.152

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	26.43
c_angle_deg	1.614
c_improper_angle_d	0.9618
c_bond_d	0.008

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2298
Nucleic Acid Atoms
Solvent Atoms	187
Heterogen Atoms	116

Software

Software
Software Name	Purpose
ADSC	data collection
CNS	refinement
HKL-2000	data reduction
HKL-2000	data scaling
CNS	phasing

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.