2BEU

Reactivity modulation of human branched-chain alpha-ketoacid dehydrogenase by an internal molecular switch


X-RAY DIFFRACTION

Starting Model(s)

Initial Refinement Model(s)
TypeSourceAccession CodeDetails
experimental modelPDB 1OLSPDB ENTRY 1OLS

Crystallization

Crystalization Experiments
IDMethodpHTemperatureDetails
1VAPOR DIFFUSION5.5293CRYSTALS WERE GROWN AT 20C VIA THE VAPOR DIFFUSION METHOD BY MIXING EQUAL AMOUNTS OF PROTEIN (20-25 MG/ML IN 50 MM HEPES/NAOH, PH 7.5, 250 MM KCL, 0.5 MM PMSF, 1 MM BENZAMIDINE AND 5% (V/V) GLYCEROL) WITH WELL SOLUTION (1.4- 1.6 M AMMONIUM SULFATE, 0.1 M NA-CITRATE PH 5.8, 20 MM B-MERCAPTOETHANOL). SERIALLY DILUTED CRUSHED CRYSTALS WERE USED FOR MICRO-SEEDING ONE DAY AFTER THE DROPS WERE SET UP. CRYSTALS APPEARED ONE DAY AFTER SEEDING AND GREW TO A MAXIMUM SIZE OF 120 X 800 UM WITHIN 10 DAYS. CRYSTALS WERE STABILIZED FOR 12 HOURS BY TRANSFER TO FRESH WELL SOLUTION. THEY WERE THEN CRYO-PROTECTED BY STEP-WISE TRANSFER INTO CRYO-BUFFER CONTAINING 1.6 M AMMONIUM SULFATE, 50 MM HEPES, PH 7.5, 100 MM NA-CITRATE, PH 5.8, 100 MM KCL, 50 MM DTT AND UP TO 20% (V/V) GLYCEROL. IT WAS FOUND THAT MANGANESE IONS COULD REPLACE THE MAGNESIUM REQUIRED FOR THE BINDING OF THDP TO THE ENZYME.
Crystal Properties
Matthews coefficientSolvent content
2.553.4

Crystal Data

Unit Cell
Length ( Å )Angle ( ˚ )
a = 145.789α = 90
b = 145.789β = 90
c = 69.525γ = 120
Symmetry
Space GroupP 31 2 1

Diffraction

Diffraction Experiment
ID #Crystal IDScattering TypeData Collection TemperatureDetectorDetector TypeDetailsCollection DateMonochromatorProtocol
11x-ray100CCDCUSTOM2003-06-21MSINGLE WAVELENGTH
Radiation Source
ID #SourceTypeWavelength ListSynchrotron SiteBeamline
1SYNCHROTRONAPS BEAMLINE 19-BMAPS19-BM

Data Collection

Overall
ID #Resolution (High)Resolution (Low)Percent Possible (Observed)R Merge 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
11.8825.6195.40.117.3665878-322.65
Highest Resolution Shell
ID #Resolution (High)Resolution (Low)Percent Possible (All)Percent Possible (Observed)R Merge I (Observed)Mean I Over Sigma (Observed)RedundancyNumber Unique Reflections (All)
11.881.9199.80.742.25.5

Refinement

Statistics
Diffraction IDStructure Solution MethodCross Validation methodStarting modelResolution (High)Resolution (Low)Number Reflections (Observed)Number Reflections (R-Free)Percent Reflections (Observed)R-Factor (Observed)R-Work (Depositor)R-Work (DCC)R-Free (Depositor)R-Free Selection DetailsMean Isotropic B
X-RAY DIFFRACTIONFOURIER SYNTHESISTHROUGHOUTPDB ENTRY 1OLS1.893063749152795.20.1710.170.20.211RANDOM17.14
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]
0.810.410.81-1.22
RMS Deviations
KeyRefinement Restraint Deviation
r_dihedral_angle_2_deg35.063
r_dihedral_angle_4_deg19.127
r_dihedral_angle_3_deg15.009
r_dihedral_angle_1_deg6.159
r_scangle_it4.515
r_scbond_it2.972
r_angle_refined_deg1.727
r_mcangle_it1.622
r_mcbond_it0.959
r_nbtor_refined0.314
Non-Hydrogen Atoms Used in Refinement
Non-Hydrogen AtomsNumber
Protein Atoms5776
Nucleic Acid Atoms
Solvent Atoms505
Heterogen Atoms47

Software

Software
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling