1RX3

DIHYDROFOLATE REDUCTASE (E.C.1.5.1.3) COMPLEXED WITH METHOTREXATE AND NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE (REDUCED FORM)

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	Other		DHFR-FOLATE-NADP COMPLEX

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		7		pH 7.0

Crystal Properties
Matthews coefficient	Solvent content
2.15	42.8

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 34.36	α = 90
b = 45.511	β = 90
c = 98.691	γ = 90

Symmetry
Space Group	P 21 21 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	293	AREA DETECTOR	XUONG-HAMLIN MULTIWIRE		1996-12-21	M

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	ROTATING ANODE	RIGAKU RUH2R

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	100	97	0.087		4.4		8086

Refinement

Statistics
Diffraction ID	Structure Solution Method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Work	R-Free	Mean Isotropic B
X-RAY DIFFRACTION	DIFFERENCE FOURIER	DHFR-FOLATE-NADP COMPLEX	2.2	20	8086		97	0.156

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	24.4
t_it	7
t_angle_deg	2.9
t_trig_c_planes	0.023
t_bond_d	0.02
t_nbd	0.02
t_gen_planes	0.008
t_incorr_chiral_ct
t_pseud_angle

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	1268
Nucleic Acid Atoms
Solvent Atoms	153
Heterogen Atoms	83

Software

Software
Software Name	Purpose
TNT	refinement
UCSD	data reduction
UCSD	data scaling
TNT	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.