1U71

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

X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	7	298	62% AS, phosphate, pH 7.0, VAPOR DIFFUSION, HANGING DROP, temperature 298K

Crystal Properties
Matthews coefficient	Solvent content
2.54	51.64

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 85.144	α = 90
b = 85.144	β = 90
c = 78.042	γ = 120

Symmetry
Space Group	H 3

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	1994-07-18	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RU200

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	2.2	50	87.1	0.058			6909	6383	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)
	2.2	2.3	60.5

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	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	wild type hDHFR	2.2	50	2	6909	6383	526	87.1	0.211	0.236	2 sigma cutoff

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_mcangle_it	0.254
p_mcbond_it	0.064
p_angle_d	0.059
p_bond_d	0.018

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1505
Nucleic Acid Atoms
Solvent Atoms	68
Heterogen Atoms	34

Software

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