4YOU

Crystal structure of a trimeric exonuclease PhoExo I from Pyrococcus horikoshii OT3 at 2.20A resolution.

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, SITTING DROP	6.7	293	CaCl2, Bis-Tris, Polyethylene glycol monomethyl ether 550

Crystal Properties
Matthews coefficient	Solvent content
2.22	44.69

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 81.94	α = 90
b = 88.98	β = 90
c = 93.95	γ = 90

Symmetry
Space Group	P 21 21 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	95	CCD	ADSC QUANTUM 315r		2008-10-26	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	PHOTON FACTORY BEAMLINE BL-5A	1.0000	Photon Factory	BL-5A

Data Collection

Overall
ID #	Resolution (High)	Resolution (Low)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	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	2.2	20	99.5	0.067	0.074	18.28	6.8		35388		-3	34.2

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	Rrim I (All)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
1	2.2	2.26	97.6		0.546	0.639	2.01

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION		FREE R-VALUE	2.2	19.963	2	35386	1772	99.7	0.1953	0.1933	0.2329	45.26

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
f_dihedral_angle_d	13.719
f_angle_d	0.891
f_chiral_restr	0.063
f_plane_restr	0.004
f_bond_d	0.003

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4972
Nucleic Acid Atoms
Solvent Atoms	97
Heterogen Atoms	3

Software

Software
Software Name	Purpose
XSCALE	data scaling
PHENIX	refinement
PDB_EXTRACT	data extraction
XDS	data reduction
MOLREP	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.