1RB3

DIHYDROFOLATE REDUCTASE COMPLEXED WITH METHOTREXATE AND NICOTINAMIDE ADENINE DINUCLEOTIDE PHOSPHATE (OXIDIZED FORM)

X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
Type	Source	Accession Code	Details
experimental model	PDB	1RB2	PDB ENTRY 1RB2

Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1		7		pH 7.0

Crystal Properties
Matthews coefficient	Solvent content
2.56	52.1

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 41.58	α = 90
b = 74.18	β = 99.26
c = 59.18	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	AREA DETECTOR	XUONG-HAMLIN MULTIWIRE		1992-07-30	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	2.3	100	96	0.096	7.7	3.2		14094

Highest Resolution Shell
ID #	Resolution (High)	Resolution (Low)	Percent Possible (All)	Percent Possible (Observed)	R-Sym I (Observed)	Mean I Over Sigma (Observed)	Redundancy	Number Unique Reflections (All)
	2.3	2.4	75		0.21	2.1	2.1

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	PDB ENTRY 1RB2	2.3	20	14094		96	0.161

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	24.5
t_it	5.6
t_angle_deg	3.1
t_nbd	0.032
t_bond_d	0.019
t_trig_c_planes	0.018
t_gen_planes	0.006
t_incorr_chiral_ct
t_pseud_angle

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2536
Nucleic Acid Atoms
Solvent Atoms	132
Heterogen Atoms	144

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.