2W3A

HUMAN DIHYDROFOLATE REDUCTASE COMPLEXED WITH NADPH AND TRIMETHOPRIM

X-RAY DIFFRACTION

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Crystallization

Crystalization Experiments
ID	Method	pH	Temperature	Details
1	VAPOR DIFFUSION, HANGING DROP	8.75	277	HUMAN DHFR/FOLATE COMPLEX WAS MIXED WITH NADPH AND TRIMETHOPRIM (BOTH 2 MM FINAL). CRYSTALS WERE GROWN BY HANGING DROP VAPOR DIFFUSION AT 277 K BY MIXING EQUAL VOLUMES OF PROTEIN/NADPH/TMP WITH RESERVOIR (24% PEG 4000, 200 MM LI2SO4, 100 MM TRIS.HCL, PH 8.75). TRUNCATED TRIANGULAR CRYSTALS APPEARED SLOWLY, IN ABOUT A MONTH. THE CRYSTAL WAS CRYOPROTECTED WITH 15% GLYCEROL AND FLASH-COOLED IN LIQUID N2.

Crystal Properties
Matthews coefficient	Solvent content
2.34	47.47

Crystal Data

Unit Cell
Length ( Å )	Angle ( ˚ )
a = 88.468	α = 90
b = 94.014	β = 90
c = 96.576	γ = 90

Symmetry
Space Group	C 2 2 21

Diffraction

Diffraction Experiment
ID #	Crystal ID	Scattering Type	Data Collection Temperature	Detector	Detector Type	Details	Collection Date	Monochromator	Protocol
1	1	x-ray	100	CCD	ADSC QUANTUM-1	MIRRORS	1997-07-14	M	SINGLE WAVELENGTH

Radiation Source
ID #	Source	Type	Wavelength List	Synchrotron Site	Beamline
1	SYNCHROTRON	CHESS BEAMLINE A1		CHESS	A1

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	1.5	20	85.7	0.05	8.3	3.3		55140		-10	16

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	1.5	1.54	28.3		0.19	2.9	1.1

Refinement

Statistics
Diffraction ID	Structure Solution Method	Cross Validation method	Starting model	Resolution (High)	Resolution (Low)	Number Reflections (Observed)	Number Reflections (R-Free)	Percent Reflections (Observed)	R-Factor (Observed)	R-Work	R-Free	R-Free Selection Details	Mean Isotropic B
X-RAY DIFFRACTION	MOLECULAR REPLACEMENT	THROUGHOUT	UNPUBLISHED HUMAN DHFR FOLATE COMPLEX	1.5	9.9	52301	2810	85.4	0.181	0.179	0.214	RANDOM	16.75

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]
0.19			0.09		-0.28

RMS Deviations
Key	Refinement Restraint Deviation
r_dihedral_angle_2_deg	37.78
r_dihedral_angle_4_deg	13.104
r_dihedral_angle_3_deg	11.995
r_dihedral_angle_1_deg	5.766
r_scangle_it	3.129
r_scbond_it	2.433
r_mcangle_it	1.633
r_angle_refined_deg	1.506
r_mcbond_it	1.377
r_angle_other_deg	1.198
r_nbd_refined	0.2
r_nbd_other	0.192
r_nbtor_refined	0.175
r_symmetry_vdw_other	0.166
r_xyhbond_nbd_refined	0.15
r_symmetry_hbond_refined	0.15
r_symmetry_vdw_refined	0.089
r_chiral_restr	0.087
r_nbtor_other	0.081
r_bond_refined_d	0.012
r_gen_planes_refined	0.006
r_bond_other_d	0.001
r_gen_planes_other	0.001
r_xyhbond_nbd_other
r_metal_ion_refined
r_metal_ion_other
r_symmetry_hbond_other
r_symmetry_metal_ion_refined
r_symmetry_metal_ion_other
r_mcbond_other
r_mcangle_other
r_scbond_other
r_scangle_other
r_long_range_B_refined
r_long_range_B_other
r_rigid_bond_restr
r_sphericity_free
r_sphericity_bonded

Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen Atoms	Number
Protein Atoms	2957
Nucleic Acid Atoms
Solvent Atoms	408
Heterogen Atoms	155

Software

Software
Software Name	Purpose
REFMAC	refinement
MOSFLM	data reduction
SCALA	data scaling
AMoRE	phasing