1IQ9

crystal structure at 1.8 A of toxin a from Naja nigricollis venom

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	4.5	291	sodium acetate, ammonium sulfate, hexane diol, pH 4.5, VAPOR DIFFUSION, SITTING DROP, temperature 291.0K

Crystal Properties
Matthews coefficient	Solvent content
2.26	45.49

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 40.9	α = 90
b = 40.9	β = 90
c = 73.5	γ = 90

Symmetry
Space Group	P 43 21 2

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	293	IMAGE PLATE	MARRESEARCH		1998-12-11	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU	1.5419

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	1.65	50	92.9	0.09	20	10	7360	7347	2	1

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)
	1.65	1.69	88.4		0.674	2.17	8	496

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Cut-off Sigma (I)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	1.8	8	2	2	7360	7347	368		0.19	0.24

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
p_angle_d	3.081
p_bond_d	0.035

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	475
Nucleic Acid Atoms
Solvent Atoms	61
Heterogen Atoms	5

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
AMoRE	phasing
X-PLOR	refinement

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 R01GM133198.