1KMS

HUMAN DIHYDROFOLATE REDUCTASE COMPLEXED WITH NADPH AND 6-([5-QUINOLYLAMINO]METHYL)-2,4-DIAMINO-5-METHYLPYRIDO[2,3-D]PYRIMIDINE (SRI-9439), A LIPOPHILIC ANTIFOLATE


X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
TypeSourceAccession CodeDetails
otherUNPUBLISHED HUMAN DHFR STRUCTURE.

Crystallization

Crystalization Experiments
IDMethodpHTemperatureDetails
1VAPOR DIFFUSION, HANGING DROP8277THE TERNARY COMPLEX OF DHFR WITH NADPH AND SRI-9439 WAS FORMED BY MIXING HUMAN DHFR (20 MG/ML IN 25 MM KPO4 (PH 7.0), 0.1 MM EDTA, AND 3 MM NAN3) WITH 60 MM NADPH, FOLLOWED 15 MINUTES LATER BY 60 MM OF INHIBITOR IN DMSO (FINAL CONCENTRATIONS OF 2 MM NADPH AND 2 MM INHIBITOR). THIS COMPLEX SOLUTION WAS MIXED WITH AN EQUAL VOLUME OF PRECIPITANT CONTAINING 24-33% PEG 4000, 0.2 M LI2SO4, 0.1 M TRIS CL (PH 7.9-8.4), AND EQUILIBRATED WITH THE PRECIPITANT BY HANGING DROP VAPOR DIFFUSION AT 277 K. THE CRYSTAL GREW IN ABOUT 3 WEEKS. THE CRYSTAL WAS FLASH-COOLED DIRECTLY IN LIQUID NITROGEN AFTER HARVESTING INTO MOTHER LIQUOR CONTAINING 10% GLYCEROL., pH 8.00, VAPOR DIFFUSION, HANGING DROP
Crystal Properties
Matthews coefficientSolvent content
2.2346

Crystal Data

Unit Cell
Length ( Å )Angle ( ˚ )
a = 41.467α = 90
b = 55.275β = 90
c = 82.799γ = 90
Symmetry
Space GroupP 21 21 21

Diffraction

Diffraction Experiment
ID #Crystal IDScattering TypeData Collection TemperatureDetectorDetector TypeDetailsCollection DateMonochromatorProtocol
11x-ray100IMAGE PLATEMARRESEARCHPT-COATED MIRROR1997-06-25MSINGLE WAVELENGTH
Radiation Source
ID #SourceTypeWavelength ListSynchrotron SiteBeamline
1SYNCHROTRONSSRL BEAMLINE BL7-1SSRLBL7-1

Data Collection

Overall
ID #Resolution (High)Resolution (Low)Percent Possible (Observed)R Merge I (Observed)R Sym I (Observed)Net I Over Average Sigma (I)RedundancyNumber Reflections (All)Number Reflections (Observed)Observed Criterion Sigma (F)Observed Criterion Sigma (I)B (Isotropic) From Wilson Plot
11.092099.60.0470.0479.43.6796117961110.8
Highest Resolution Shell
ID #Resolution (High)Resolution (Low)Percent Possible (All)Percent Possible (Observed)R Merge I (Observed)R-Sym I (Observed)Mean I Over Sigma (Observed)RedundancyNumber Unique Reflections (All)
1.091.1599.10.4220.4222.33.3

Refinement

Statistics
Diffraction IDStructure Solution MethodCross Validation methodStarting modelResolution (High)Resolution (Low)Number Reflections (All)Number Reflections (Observed)Number Reflections (R-Free)Percent Reflections (Observed)R-WorkR-FreeR-Free Selection DetailsMean Isotropic B
X-RAY DIFFRACTIONMOLECULAR REPLACEMENTTHROUGHOUTUNPUBLISHED HUMAN DHFR STRUCTURE.1.09207941179411398899.60.13060.17265% OF THE REFLECTIONS WERE RANDOMLY SELECTED FOR THE TEST SET.
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]
Coordinate Error
Structure Solution MethodRefinement High ResolutionRefinement Low Resolution
661406.121927.22
RMS Deviations
KeyRefinement Restraint Deviation
s_approx_iso_adps0.098
s_non_zero_chiral_vol0.086
s_zero_chiral_vol0.076
s_similar_adp_cmpnt0.05
s_angle_d0.032
s_from_restr_planes0.0293
s_anti_bump_dis_restr0.023
s_bond_d0.013
s_rigid_bond_adp_cmpnt0.005
s_similar_dist
Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen AtomsNumber
Protein Atoms1606
Nucleic Acid Atoms
Solvent Atoms399
Heterogen Atoms83

Software

Software
Software NamePurpose
AMoREphasing
SHELXL-97refinement
MOSFLMdata reduction
CCP4data scaling