1I8F

THE CRYSTAL STRUCTURE OF A HEPTAMERIC ARCHAEAL SM PROTEIN: IMPLICATIONS FOR THE EUKARYOTIC SNRNP CORE

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8.3	293	PEG-4000, acetate, glycerol, pH 8.3, VAPOR DIFFUSION, HANGING DROP, temperature 293.0K

Crystal Properties
Matthews coefficient	Solvent content
2.38	48.34

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 100.261	α = 90
b = 95.738	β = 92.69
c = 62.157	γ = 90

Symmetry
Space Group	C 1 2 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	105	CCD	ADSC QUANTUM 4	collimating mirror optics, double-slit monochromator	2000-11-05	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	NSLS BEAMLINE X8C	0.9794	NSLS	X8C

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	1.71	100	98.5	0.04	44.4	6.48	62547	62547		-3

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)
1	1.71	1.77	97.2		0.723

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	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	MAD	1.75	20	59011	56641	2839	96	0.235	0.266	RANDOM	38.5

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
c_dihedral_angle_d	26.232
c_angle_deg	1.8962
c_improper_angle_d	1.2245
c_bond_d	0.01809

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3815
Nucleic Acid Atoms
Solvent Atoms	130
Heterogen Atoms	30

Software

Software
Software Name	Purpose
MLPHARE	phasing
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling

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.