2P7F

The Novel Use of a 2',5'-Phosphodiester Linkage as a Reaction Intermediate at the Active Site of a Small Ribozyme

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1ZFR	PDB ENTRY 1ZFR

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7	293	250 mM Li2SO4, 2.5 mM [Co(NH3)6]Cl3, 2 mM spermidine-HCl, 15 mM nicotinic acid, 100 mM sodium HEPES buffer and 20.5% PEG 2000 MME, pH 7.0, VAPOR DIFFUSION, HANGING DROP, temperature 293K

Crystal Properties
Matthews coefficient	Solvent content
4.11	79.8

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 94.1	α = 90
b = 94.1	β = 90
c = 127.2	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	CCD	ADSC QUANTUM 315	Flat mirror (vertical focusing); single crystal Si(111) bent monochromator (horizontal focusing)	2006-04-21	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL11-1	0.97945	SSRL	BL11-1

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	2.35	40.76	99.1	0.037	19.6	5.92	14321	14321		-3	90.5

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)
	2.35	2.43	99.1		0.448	2.9	5.32

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	PDB ENTRY 1ZFR	2.35	29.38	14313	14313	724	99	0.226	0.226	0.227	0.252	RANDOM	81.7

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]
-13.01	-2.59		-13.01		26.02

RMS Deviations
Key	Refinement Restraint Deviation
c_dihedral_angle_d	17.3
c_improper_angle_d	1.86
c_angle_deg	1.4
c_bond_d	0.008
c_mcbond_it
c_mcangle_it
c_scbond_it
c_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	1310
Solvent Atoms	15
Heterogen Atoms	19

Software

Software
Software Name	Purpose
Blu-Ice	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 R01GM157729.