SOLUTION NMR Experimental Data

Experimental Details
Sample Conditions
Sample Contents1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.0;
Solvent95% H2O/5% D2O
Ionic Strength100mM KCl
Temperature (K)305
Experiment(s):3D HNCO (NH coupled), 3D HNCO (C'CA coupled), CBCA(CO)NH (Quantitative J), TROSY HNCO (Quantitative J), HNCOCA (C'HA coupled), 3D 13C-separated NOESY
Spectrometer Information
Manufacturer Model Field Strength
Bruker Avance 750.0
Bruker Avance 600.0
Bruker Avance 500.0
NMR Refinement
Method simulated annealing
Details This structure is determined mainly by residual dipolar couplings measured in A liquid crystalline Pf1 medium. The structure calculation scheme, described in the paper, is based on the idea of refining existing structural models against dipolar couplings to derive the correct structure. Here a total of 305 backbone dipolar couplings are used to refine the backbone structure. Additionally, 35 sidechain dipolar couplings and 81 3-bond J couplings are used to determine the sidechain chi1 and chi2 rotamers as well as the presence of rotameric averaging. A total of three structures (model 1-3) were calculated starting from the 1. A crystal structure of Ca-calmodulin (PDB entry 1EXR), the NMR structure of apo-calmodulin (1F70), and the crystal structure of Ca-ligated parvalbumin (1CDP). The convergence of refinement is indicated by the small average RMSD between the three calculated structures and the average coordinates (0.26 A for backbone and 0.90 for all heavy atoms). During the three-stage simulated annealing described in the paper, restraints are included for most previously established hydrogen bonds, but have only minute effects (< 0.3 A) on the final structure.
NMR Ensemble Information
Conformer Selection Criteria structure with the lowest dipolar energy
Conformers Calculated Total Number 3
Conformers Submitted Total Number 3
Representative Model Choice Rationale
1 lowest dipolar energy
Additional NMR Experimental Information
1 A total of five sets of dipolar couplings are measured, including the one-bond NH, CAHA, C'CA, and NC' couplings, and the two-bond C'HA couplings. Additionally, the CBHB dipolar couplings were measure to assign chi-1 rotamers for locked sidechains.
Computation: NMR Software
# Classification Software Name Author
1 refinement version: 3.851 X-PLOR Brunger
2 processing version: 2.0 NMRPipe Delaglio