8F5W

Dihydropyrimidine Dehydrogenase (DPD) C671S Mutant Soaked with Dihydrothymine and NADPH Quasi-Anaerobically


X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
TypeSourceAccession CodeDetails
experimental modelPDB 7M31 

Crystallization

Crystalization Experiments
IDMethodpHTemperatureDetails
1VAPOR DIFFUSION, HANGING DROP293DPD variant C671S (39.2 uM) in 25 mM HEPES, 2 mM DTT, 10% glycerol at pH 7.5 was mixed 1:1 with well solution containing 100 mM sodium citrate, 2 mM DTT, 19% PEG 6000 at pH 4.7 to yield a 6 uL drop. Crystallization was carried out in the dark to prevent photo-degradation of the somewhat dissociable FMN cofactor. Under these conditions DPD crystals appeared within 16 hours and were left to grow for additional 24 hours. Ligands were combined with the crystals under near anaerobic conditions as follows: before being placed in a Plas-Labs 830 series glove box, the well solution beneath selected crystallization drops were made anaerobic with the addition of 10 mM dithionite and resealed with the cover slide. Crystals trays were placed in the glove box that contained a Motic binocular microscope coupled to an Accuscope 1080p high-definition camera. The glove box was sealed and made quasi-anaerobic by flushing with high-purity nitrogen gas for approximately 10 minutes at which time fractional dioxygen was recorded as 0.1 %, by a Forensics Detectors oxygen meter. Atmospheric dioxygen was measured throughout the soaking procedure and was held <1%. C671S DPD crystals were soaked for a minimum of 20 minutes with DHT (R,S) (200 uM) and NADPH (100 uM), each dissolved in the following cryo-solution: 20 mM sodium citrate, 0.4 mM DTT, 20% PEG 6000, 20% PEG 400, pH 7.5. The crystals were then submerged in liquid nitrogen, removed from the anaerobic environment, and stored under liquid nitrogen.
Crystal Properties
Matthews coefficientSolvent content
2.3447.4

Crystal Data

Unit Cell
Length ( Å )Angle ( ˚ )
a = 81.735α = 90
b = 158.003β = 96.06
c = 162.404γ = 90
Symmetry
Space GroupP 1 21 1

Diffraction

Diffraction Experiment
ID #Crystal IDScattering TypeData Collection TemperatureDetectorDetector TypeDetailsCollection DateMonochromatorProtocol
11x-ray100PIXELDECTRIS EIGER X 9M2022-06-08MSINGLE WAVELENGTH
Radiation Source
ID #SourceTypeWavelength ListSynchrotron SiteBeamline
1SYNCHROTRONAPS BEAMLINE 21-ID-D1.1272APS21-ID-D

Data Collection

Overall
ID #Resolution (High)Resolution (Low)Percent Possible (Observed)R Merge I (Observed)Rrim I (All)Rpim I (All)CC (Half)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
11.9747.2398.60.13010.1510.0750.99410428343526.48
Highest Resolution Shell
ID #Resolution (High)Resolution (Low)Percent Possible (All)Percent Possible (Observed)R Merge I (Observed)Rrim I (All)Rpim I (All)CC (Half)Mean I Over Sigma (Observed)RedundancyNumber Unique Reflections (All)
11.972.0195.20.90941.1290.5590.6331.14

Refinement

Statistics
Diffraction IDStructure Solution MethodCross Validation methodStarting modelResolution (High)Resolution (Low)Cut-off Sigma (F)Number Reflections (Observed)Number Reflections (R-Free)Percent Reflections (Observed)R-Factor (Observed)R-WorkR-FreeMean Isotropic B
X-RAY DIFFRACTIONMOLECULAR REPLACEMENTTHROUGHOUT7M311.9747.231.352832191406798.510.18060.17870.21732.5455
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]
Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen AtomsNumber
Protein Atoms30850
Nucleic Acid Atoms
Solvent Atoms977
Heterogen Atoms692

Software

Software
Software NamePurpose
xia2data reduction
xia2data scaling
PHASERphasing
PHENIXrefinement
PDB_EXTRACTdata extraction