1E9N

A second divalent metal ion in the active site of a new crystal form of human apurinic/apyrimidinic endonuclease, Ape1, and its implications for the catalytic mechanism

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5		HANGING DROP, DROP 2+2 UL, 15MG/ML PROTEIN, 1 ML WELL, 0.1M TRIS-HCL, PH 7.5, 0.2M NAOAC, 30% PEG4K, 20MM HECAMEG, 1MM PB(OAC)2, 1MM DTT

Crystal Properties
Matthews coefficient	Solvent content
2.6	53

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 137.522	α = 90
b = 45.016	β = 108.03
c = 125.702	γ = 90

Symmetry
Space Group	C 1 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	110	CCD	ADSC CCD	DUAL CRYSTAL MIRROR	1999-07-15	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	SSRL BEAMLINE BL11-1		SSRL	BL11-1

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	2.2	67.42	93	0.082	11.8	2.9		34905

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	2.2	2.32	70.5		0.379	2.1	2

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	TO BE PUBLISHED	2.2	20	34905	31342		93	0.186	0.252

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
t_dihedral_angle_d	18.92
t_it	3.2
t_angle_deg	2.32
t_nbd	0.228
t_bond_d	0.018
t_gen_planes	0.016
t_trig_c_planes	0.007
t_incorr_chiral_ct
t_pseud_angle
t_omega_torsion

RMS Deviations
Key	Refinement Restraint Deviation
t_dihedral_angle_d	18.92
t_it	3.2
t_angle_deg	2.32
t_nbd	0.228
t_bond_d	0.018
t_gen_planes	0.016
t_trig_c_planes	0.007
t_incorr_chiral_ct
t_pseud_angle
t_omega_torsion
t_other_torsion
t_improper_torsion
t_chiral_improper_torsion
t_sum_occupancies
t_utility_distance
t_utility_angle
t_utility_torsion
t_ideal_dist_contact

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	4336
Nucleic Acid Atoms
Solvent Atoms	349
Heterogen Atoms	4

Software

Software
Software Name	Purpose
TNT	refinement
MOSFLM	data reduction
SCALA	data scaling
EPMR	phasing

RCSB PDB Core Operations are funded by the National Science Foundation (DBI-1832184), 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 R01GM133198.