3CQS

A 3'-OH, 2',5'-phosphodiester substitution in the hairpin ribozyme active site reveals similarities with protein ribonucleases

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.5	293	20.5% (w/v) PEG 2000 MME, 0.10 M Na cacodylate buffer, 0.25 M Li2SO4, 2.5 mM Co(NH3)6Cl3, 2 mM spermidine-HCl, pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 293K

Crystal Properties
Matthews coefficient	Solvent content
4.08	69.86

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 93.16	α = 90
b = 93.16	β = 90
c = 129.05	γ = 120

Symmetry
Space Group	P 61 2 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	confocal	2007-04-07	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RUH2R	1.5418

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	2.8	34.2		0.056	15.5	5.09		8458		-3	98.26

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)
	2.8	2.9			0.445	1.4	4.8	834

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	FOURIER SYNTHESIS	THROUGHOUT	2p7f	2.8	22.92	8635	8446	621	97.8	0.22	0.22	0.217	0.254	Test set reflections matched to those of starting model. Additional reflections flagged at random to exclude 7.4% total.	82.2

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]
-13.93			-13.93		27.87

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	18
c_improper_angle_d	1.83
c_angle_deg	1.5
c_bond_d	0.009

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	1327
Solvent Atoms	6
Heterogen Atoms	7

Software

Software
Software Name	Purpose
CrystalClear	data collection
CNS	refinement
CrystalClear	data reduction
CrystalClear	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.