1JWD

Ca2+-induced Structural Changes in Calcyclin: High-resolution Solution Structure of Ca2+-bound Calcyclin.

SOLUTION NMR

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D NOESY	2 mM calcyclin, 50 MM TRIS buffer, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
2	3D_13C-separated_NOESY	2 mM 15N, 13C-enriched calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
3	3D_15N-separated_NOESY	2 mM 15N, 13C-enriched calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
4	3D_HACAHB	2 mM 15N, 13C-enriched calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
5	3D_13C-filter,13C-edited_NOESY	1:1 15N,13C-enriched:unlabled calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
6	3D_15N-separated_NOESY	15N-enriched calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	90% H2O/10% D2O	30 mM CaCl2	7.0	ambient	300
7	2D_13C_HSQC	10% 13C-enriched calcyclin, 50 mM TRIS-buffer, 0.05% NaN3, 30 mM CaCl2	D2O	30 mM CaCl2	7.0	ambient	300

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	DMX	750
2	Bruker	DRX	600
3	Bruker	AMX	500

NMR Refinement
Method	Details	Software
distance geometry, restrained molecular dynamics	The calculations were carried out using a total of 3104 distance and 294 torsion angle constraints. Starting structures were generated as monomers (one chain) with no intersubunit constraints using distance geometry followed by restrained molecular dynamics (rMD). The dimer structures were generated by rMD docking driven by the intersubunit NOEs using two arbitrarily selected starting subunit structures. Each dimer was further refined by rMD with all constraints.	Felix

NMR Ensemble Information
Conformer Selection Criteria	The program Findfam was used to establish that the number of structures required to accurately represent the ensemble was less than 22 (the number selected to represent previous S100A6 ensembles). Structures were ordered by lowest restraint violations, then accepted if total molecular energy and each contributing term was within two standard deviations of the mean. The 22 structures with least restraint violations (energy penalty and magnitude of largest violation) all met these criteria.
Conformers Calculated Total Number	100
Conformers Submitted Total Number	22
Representative Model	1 (closest to the average)

Additional NMR Experimental Information
Details	Dimer constraints were obtained from the 3D_13C-filter,13C-edited experiment in combination with 3D_13C-separated_NOESY

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	data analysis	Felix	97	MSI
2	structure solution	DIANA	2.8	Guntert, Braun & Wuthrich
3	refinement	Amber	4.1	Pearlmann, Case, Caldwell, Ross, Cheatham III, Ferguson, Seibel, Singh, Weiner & Kollman
4	data analysis	FINDFAM	1.0	Smith, Chazin & Case

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.