2BFB

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


X-RAY DIFFRACTION

Crystallization

Crystalization Experiments
IDMethodpHTemperatureDetails
1VAPOR DIFFUSION5.5295CRYSTALS WERE GROWN AT 22C VIA THE VAPOR DIFFUSION METHOD IN COMPLEX WITH A 40 AMINO ACID PEPTIDE DERIVED FROM THE SUBUNIT BINDING DOMAIN (SBD) OF THE E2 COMPONENT OF BRANCHED CHAIN ALPHA-KETOACID DEHDROGENASE. THIS COMPLEX WAS FORMED BY MIXING N-TERMINALLY HIS6-TAGGED PROTEIN WITH C-TERMINALLY HIS6-TAGGED SBD IN 50 MM NA-HEPES, PH 7.5, 150 MM KCL, 20 MM DTT AND 5% (V/V) GLYCEROL AT A MOLAR RATIO OF 1:4. CRYSTALS OF THE COMPLEX (20 MG/ML) WERE OBTAINED BY MIXING 3 MICROLITERS OF PROTEIN WITH 3 MICROLITERS OF CRYSTALLIZATION SOLUTION (10% (V/V) POLYETHYLENE GLYCOL 4000, 10% (V/V) MPD AND 0.1M SODIUM CITRATE, PH 5.8) WITH 1 ML OF CRYSTALLIZATION SOLUTION IN THE RESERVOIR. MANGANESE IONS WERE USED INSTEAD OF MAGNESIUM REQUIRED FOR THE BINDING OF THIAMIN DIPHOSPHATE TO THE ENZYME. THE PRESENCE OF MANGANESE IONS IN THE CRYSTALS RESULTED IN IMPROVED X-RAY DIFFRACTION QUALITIES WITHOUT AFFECTING THE CATALYTIC PROPERTIES. CRYSTALS WERE CRYO-PROTECTED BY STEP-WISE TRANSFER INTO CRYO-BUFFER (CRYSTALLIZATION SOLUTION CONTAINING 5-10%(V/V) GLYCEROL).
Crystal Properties
Matthews coefficientSolvent content
2.553.4

Crystal Data

Unit Cell
Length ( Å )Angle ( ˚ )
a = 145.781α = 90
b = 145.781β = 90
c = 69.372γ = 120
Symmetry
Space GroupP 31 2 1

Diffraction

Diffraction Experiment
ID #Crystal IDScattering TypeData Collection TemperatureDetectorDetector TypeDetailsCollection DateMonochromatorProtocol
11x-ray100CCDCUSTOM2004-04-12MSINGLE WAVELENGTH
Radiation Source
ID #SourceTypeWavelength ListSynchrotron SiteBeamline
1SYNCHROTRONAPS BEAMLINE 19-IDAPS19-ID

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
11.7726.7799.70.0919.46.582758-318.88
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)
11.771.899.90.7424.4

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-WorkR-FreeR-Free Selection DetailsMean Isotropic B
X-RAY DIFFRACTIONMOLECULAR REPLACEMENTTHROUGHOUTPDB ENTRY 1OLS1.773081272145599.70.1450.1450.184RANDOM17.05
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]
0.440.220.44-0.66
RMS Deviations
KeyRefinement Restraint Deviation
r_dihedral_angle_2_deg34.248
r_dihedral_angle_4_deg17.679
r_dihedral_angle_3_deg14.15
r_dihedral_angle_1_deg5.792
r_scangle_it4.603
r_scbond_it2.917
r_angle_refined_deg1.672
r_mcangle_it1.657
r_mcbond_it0.954
r_nbtor_refined0.312
RMS Deviations
KeyRefinement Restraint Deviation
r_dihedral_angle_2_deg34.248
r_dihedral_angle_4_deg17.679
r_dihedral_angle_3_deg14.15
r_dihedral_angle_1_deg5.792
r_scangle_it4.603
r_scbond_it2.917
r_angle_refined_deg1.672
r_mcangle_it1.657
r_mcbond_it0.954
r_nbtor_refined0.312
r_nbd_refined0.217
r_symmetry_hbond_refined0.207
r_symmetry_vdw_refined0.186
r_xyhbond_nbd_refined0.151
r_chiral_restr0.131
r_bond_refined_d0.019
r_gen_planes_refined0.009
r_bond_other_d
r_angle_other_deg
r_gen_planes_other
r_nbd_other
r_nbtor_other
r_xyhbond_nbd_other
r_metal_ion_refined
r_metal_ion_other
r_symmetry_vdw_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 AtomsNumber
Protein Atoms5523
Nucleic Acid Atoms
Solvent Atoms644
Heterogen Atoms45

Software

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