1J7O | pdb_00001j7o

Solution structure of Calcium-calmodulin N-terminal domain


SOLUTION NMR
NMR Experiment
ExperimentTypeSample ContentsSolventIonic StrengthpHPressureTemperature (K)Spectrometer
13D HNCO (NH coupled)1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
23D HNCO (COCA coupled)1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
3CBCA(CO)NH (Quantitative J)1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
4HNCOCA (COHA coupled)1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
53D TROSY-HNCO (Quantitative J)1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
63D 13C-separated NOESY1mM calmodulin U-15N,13C; 100mM KCl, 16mM CaCl2, pH 7.095% H2O/5% D2O100mM KCl7.0ambient305
NMR Spectrometer Information
SpectrometerManufacturerModelField Strength
1BrukerAVANCE500
2BrukerAVANCE600
3BrukerAVANCE750
NMR Refinement
MethodDetailsSoftware
simulated annealingThis 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 thecorrect structure. Here a total of 323 backbone dipolar couplings are used to refine the backbone structure. Additionally, 38 sidechain dipolar couplings and 85 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 (0.28 A for backbone and 0.87 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.X-PLOR
NMR Ensemble Information
Conformer Selection Criteriastructure with lowest dipolar energy
Conformers Calculated Total Number3
Conformers Submitted Total Number3
Representative Model2 (lowest dipolar energy)
Additional NMR Experimental Information
DetailsA 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 sidechain CBHB dipolar couplings are measured to assign chi-1 rotamers for locked sidechains.
Computation: NMR Software
#ClassificationVersionSoftware NameAuthor
1refinementX-PLOR3.851Brunger
2processingNMRPipe2.0Delaglio