1HW4

STRUCTURE OF THYMIDYLATE SYNTHASE SUGGESTS ADVANTAGES OF CHEMOTHERAPY WITH NONCOMPETITIVE INHIBITORS

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.8	298	ammonium sulfate, tris buffer, potassium phosphate, and 2-mercaptoethanol, pH 7.8, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.68	54.08

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 95.68	α = 90
b = 95.68	β = 90
c = 82.998	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	120	CCD	SBC-1	Monochromators	2000-08-25	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	APS BEAMLINE 19-ID	0.9793	APS	19-ID

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	2.06	20	96	0.051	36	5.7	27419	26475	2	2	19.2

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	2.06	2.13	99.8		0.373		5.7

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Resolution (High)	Resolution (Low)	Cut-off Sigma (I)	Cut-off Sigma (F)	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	MOLECULAR REPLACEMENT	THROUGHOUT	2.06	6	2	3	28871	22853	1123	86.7	0.224	0.24	RANDOM	41.7

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_dihedral_angle_d	23.9
c_scangle_it	2.76
c_mcangle_it	2.17
c_scbond_it	1.91
c_mcbond_it	1.34
c_angle_deg	1.3
c_improper_angle_d	0.87
c_bond_d	0.006

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2137
Nucleic Acid Atoms
Solvent Atoms	102
Heterogen Atoms	19

Software

Software
Software Name	Purpose
CNS	refinement
d*TREK	data reduction
SCALEPACK	data scaling
CNS	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.