1U70

Understanding the Role of Leu22 Variants in Methotrexate Resistance: Comparison of Wild-type and Leu22Arg Variant Mouse and Human Dihydrofolate Reductase

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7.5	298	20% PEG 4k 0.1 M HEPES, pH 7.5, VAPOR DIFFUSION, HANGING DROP, temperature 298K
2	VAPOR DIFFUSION, HANGING DROP	7	298	62% AS, 0.1M phosphate , pH 7.0, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 42.016	α = 90
b = 61.536	β = 116.69
c = 43.572	γ = 90

Symmetry
Space Group	P 1 21 1

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	298	IMAGE PLATE	RIGAKU RAXIS IIC	mirrors	1997-06-25	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU300

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	2.5	50		0.055			6963	6792	2	2

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.5	2.56	96.1

Refinement

Statistics
Diffraction ID	Structure Solution Method	Resolution (High)	Resolution (Low)	Cut-off Sigma (F)	Number Reflections (All)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (All)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	2.5	50	2	6963	6792	217		0.225	0.225	0.183	0.225	two sigma cutoff	39.6

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
p_mcbond_it	0.247
p_mcangle_it	0.069
p_angle_d	0.064
p_bond_d	0.017

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1516
Nucleic Acid Atoms
Solvent Atoms	27
Heterogen Atoms	81

Software

Software
Software Name	Purpose
DENZO	data reduction
SCALEPACK	data scaling
PROTEIN	model building
PROFFT	refinement
PROTEIN	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.