1A73

INTRON-ENCODED ENDONUCLEASE I-PPOI COMPLEXED WITH DNA

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	5.6		THE CRYSTALS WERE GROWN FROM A 2:1 MOLAR RATIO SOLUTION OF PROTEIN AND DNA SUPPLEMENTED WITH 2.5 MM EDTA AND 5 MM SPERMINE. THE COMPLEX WAS CRYSTALLIZED FROM 21 - 27% PEG 4000, 0.1 M CITRATE, PH 5.4 - 5.8, 20 MM NACL, 2 MM EDTA., pH 5.6, VAPOR DIFFUSION, HANGING DROP

Crystal Properties
Matthews coefficient	Solvent content
3.4	60

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 113.7	α = 90
b = 113.7	β = 90
c = 88.4	γ = 120

Symmetry
Space Group	P 31 2 1

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	NONE	1997-12-15	M

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)	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	1.8	50	99.8	0.049	0.049	19.1	5.04		362336		2

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R Merge I (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	1.8	1.9	99.7		0.12	0.12	4.9	4.97

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	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MULTIPLE ISOMORPHOUS REPLACEMENT	THROUGHOUT	1.8	50	2	71629	3581	99.4	0.208	0.208	0.297	RANDOM	32.5

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_dihedral_angle_d	27.2
x_improper_angle_d	1.7
x_angle_deg	1.3
x_bond_d	0.01
x_bond_d_na
x_bond_d_prot
x_angle_d
x_angle_d_na
x_angle_d_prot
x_angle_deg_na
x_angle_deg_prot
x_dihedral_angle_d_na
x_dihedral_angle_d_prot
x_improper_angle_d_na
x_improper_angle_d_prot
x_mcbond_it
x_mcangle_it
x_scbond_it
x_scangle_it

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2490
Nucleic Acid Atoms	856
Solvent Atoms	391
Heterogen Atoms	6

Software

Software
Software Name	Purpose
CCP4	model building
X-PLOR	refinement
MOSFLM	data reduction
CCP4	data scaling
ROTAVATA	data scaling
CCP4	phasing