2KX9

Solution Structure of the Enzyme I dimer Using Residual Dipolar Couplings and Small Angle X-Ray Scattering

SOLUTION NMR - SOLUTION SCATTERING

---

Solution Scattering Data Acquistion	1	2
Scattering Type	x-ray	neutron
Radiation/Neutron Source	ALS	NIST NCNR
Synchrotron	Y	N
Beamline Type	2.12-IDC	30M NG3
Detector Type	Gold CCD
Detector Manufacturer Details
Temperature (K)	298	298
pH	7.4	7.4
Numer of Time Frames Used	20
Protein Concentration Range (mg/mL)	2.5-5	5
Sample Buffer
Data Reduction Software
Guiner Mean Radius Of Gyration (nm)	41.9	44.2
Sigma Mean Radius Of Gyration
R(XS-1) Mean Cross Sectional Radii (nm)
R(XS-1) Sigma Mean Cross Sectional Radii
R(XS-2) Mean Cross Sectional Radii (nm)
R(XS-2) Sigma Mean Cross Sectional Radii
P(R) Protein Length (nm)	150	150

Solution Scattering Data Analysis and Model Fitting
Method	Software	Software Authors	Starting Model	Conformers, Number Calculated	Conformers, Number Submitted	Conformers, Selection Criteria	Best Representative Conformer	Other Details
	GNOM,XPLOR-NIH		PDB ENTRIES 2HWG AND 3EZA	99	1	REGULARIZED MEAN OF 99 MODELS	1	The initial structure of the EI dimer was constructed as a hybrid of the crystal structure of phosphorylated EI intermediate captured by the inhibitor oxalate (PDB code 2HWG) and the NMR structure of the EIN-HPr complex (PDB code 3EZA). Throughout the structure determination, the backbone atomic coordinates of each EIN domain (residues 1-254) were treated as rigid bodies, with the two symmetry related EIC domains (residues 262- 573) held fixed in space. Coordinates in the linker region (residues 255-261) were allowed varying degrees of freedom during the calculation through the use of the internal variable module (IVM) of Xplor-NIH. This entry corresponds to the regularized mean of the 99 structures for which data was reported in the primary publication, with the B-factor column representing the per-atom spread (in B-factor units). The calculated structural statistics for the original 99 structures and for the regularized mean are shown below.

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	TROSY-based 1H-15N correlation spectroscopy	20 mM TRIS, 100 mM sodium chloride, 10 mM DTT, 4 mM MgCl2, 1 mM EDTA, 10 % D2O, 1 tablet protease inhibitor, 0.15 mM EI dimer	90% H2O/10% D2O		7.4	ambient	310

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	DRX	800

NMR Refinement
Method	Details	Software
simulated annealing	STRUCTURE STATISTICS: MODEL 1: SAXS CHI2 Q->0.44: 0.43 SAXS CHI2 FULL RANGE: 2.26 SANS CHI2: 0.39 RDC R-FACTOR: 18.03 % RDC DA: 14.5 HZ RDC RH: 0.49 MODEL 2: SAXS CHI2 Q->0.44: 0.40 SAXS CHI2 FULL RANGE: 1.99 SANS CHI2: 0.58 RDC R-FACTOR: 18.07 RDC DA: 14.5 HZ RDC RH: 0.48 AVERAGE OVER THE FULL 99-MEMBER ENSEMBLE: SAXS CHI2 Q->0.44: 0.29 +/- 0.05 SAXS CHI2 FULL RANGE: 1.34 +/- 0.27 SANS CHI2: 0.41 +/- 0.08 RDC R-FACTOR: 18.07 +/- 0.02 % RDC DA: 14.5 +/- 0.1 HZ RDC RH: 0.49 +/- 0.00	Xplor-NIH

NMR Ensemble Information
Conformer Selection Criteria	target function
Conformers Calculated Total Number	120
Conformers Submitted Total Number	2
Representative Model	1 (closest to the average)

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	structure solution	Xplor-NIH	2.25	Schwieters, Kuszewski, Tjandra and Clore
2	refinement	Xplor-NIH	2.25	Schwieters, Kuszewski, Tjandra and Clore