Experiment: 3NKB

A 1.9A crystal structure of the HDV ribozyme precleavage suggests both Lewis acid and general acid mechanisms contribute to phosphodiester cleavage

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1CX0	PDB ENTRY 1CX0 WITH PORTIONS OF P2 AND P4 DELETED

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	5	293	3.5 mg/mL RNA, 10 mM MgCl2, 50 mM potassium acetate, 1 mM spermine, 30% MPD, pH 5.0, VAPOR DIFFUSION, HANGING DROP, temperature 293K

Crystal Properties
Matthews coefficient	Solvent content
2.97	58.62

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 64.837	α = 90
b = 84.107	β = 90
c = 102.02	γ = 90

Symmetry
Space Group	C 2 2 21

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	MARMOSAIC 225 mm CCD		2010-03-15	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 21-ID-F	0.97872	APS	21-ID-F

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	1.9	50	94.3	0.055	44.3	7.2		20583		1	35.67

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)
	1.9	1.95	54.6		0.423	2.2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free (DCC)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	PDB ENTRY 1CX0 WITH PORTIONS OF P2 AND P4 DELETED	1.916	27.361	0.11	19845	1994	91.1	0.2169	0.2141	0.2109	0.241	0.2371	random	41.2488

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]
0.624			3.8266		-4.4506

RMS Deviations
Key	Refinement Restraint Deviation
f_dihedral_angle_d	15.206
f_angle_d	1.254
f_chiral_restr	0.078
f_plane_restr	0.005
f_bond_d	0.003

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms
Nucleic Acid Atoms	1538
Solvent Atoms	168
Heterogen Atoms	10

Software

Software
Software Name	Purpose
PHENIX	refinement
PDB_EXTRACT	data extraction
HKL-2000	data reduction
HKL-2000	data scaling
PHASER	phasing