Experiment: 1FXX

THE STRUCTURE OF EXONUCLEASE I SUGGESTS HOW PROCESSIVITY IS ACHIEVED

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	6	298	1.85 - 2.0M Na/K Phosphate, 20% v/v Glycerol, pH 6.00, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.77	55.52

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 84.41	α = 90
b = 84.41	β = 90
c = 298.65	γ = 120

Symmetry
Space Group	P 65 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	277	IMAGE PLATE	MARRESEARCH		1999-01-19	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL9-1		SSRL	BL9-1

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	2.4	20	95.9	0.05	14.4	5.9	25722	24672			42.5

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)
1	2.4	2.46	96.2		0.267		5.7

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-Factor (All)	R-Factor (Observed)	R-Work (Depositor)	R-Work (DCC)	R-Free (Depositor)	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION		2.4	20	25660	24603	1225	95.9	0.2202	0.2202	0.2038	0.2152	0.2364	RANDOM

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
c_angle_deg	1.5
c_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	3728
Nucleic Acid Atoms
Solvent Atoms	102
Heterogen Atoms	12

Software

Software
Software Name	Purpose
SHARP	phasing
CNS	refinement
DENZO	data reduction
SCALEPACK	data scaling