1NU4

U1A RNA binding domain at 1.8 angstrom resolution reveals a pre-organized C-terminal helix

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1URN	pdb entry 1urn

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	5	298	Potassium Malonate, pH 5.0, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.18	43.56

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 91.819	α = 90
b = 91.819	β = 90
c = 120.448	γ = 120

Symmetry
Space Group	H 3 2

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	IMAGE PLATE	RIGAKU RAXIS IV	osmics mirrors	2002-08-15	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU300	1.5418

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (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	1.8	30	96.2	0.031	0.031	37.6	4	18308	17618			31.1

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	1.8	1.86	76.8		0.311	0.311	2.46	1.4	1365

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (All)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	pdb entry 1urn	1.8	29.16	18308	17616	1749	96.1	0.203	0.203	0.203	0.234	RANDOM	40.3

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]
1.15	2.83		1.15		-2.3

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	22.8
c_scangle_it	5.74
c_scbond_it	4.16
c_mcangle_it	4.01
c_mcbond_it	2.82
c_angle_deg	1.1
c_improper_angle_d	0.64
c_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1450
Nucleic Acid Atoms
Solvent Atoms	99
Heterogen Atoms	89

Software

Software
Software Name	Purpose
CNS	refinement
DENZO	data reduction
SCALEPACK	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 R01GM133198.