1EVX

APO CRYSTAL STRUCTURE OF THE HOMING ENDONUCLEASE, I-PPOI

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6.5	277	ammonium sulfate, PEG 8K, sodium cacodylate pH 6.5, VAPOR DIFFUSION, HANGING DROP, temperature 4K

Crystal Properties
Matthews coefficient	Solvent content
2.75	55.2

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 52.8	α = 90
b = 52.8	β = 90
c = 278.8	γ = 90

Symmetry
Space Group	P 41 21 2

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	77	CCD				M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	ALS BEAMLINE 5.0.2		ALS	5.0.2

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	2	50	90.8	0.052	12.2	4	102030	25509

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)
	2	2.03	74.8		0.204

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		2	50	102030	25509	1530		0.194	0.229	6% of reflections

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
x_torsion_deg	26.9
x_angle_deg	1.3
x_torsion_impr_deg	0.67
x_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2490
Nucleic Acid Atoms
Solvent Atoms	310
Heterogen Atoms	24

Software

Software
Software Name	Purpose
EPMR	phasing
X-PLOR	refinement
DENZO	data reduction
SCALEPACK	data scaling

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.