1AQ5

HIGH-RESOLUTION SOLUTION NMR STRUCTURE OF THE TRIMERIC COILED-COIL DOMAIN OF CHICKEN CARTILAGE MATRIX PROTEIN, 20 STRUCTURES

SOLUTION NMR

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D NOESY				5.5		323
2	2D TOCSY				5.5		323
3	2D 1H-15N HSQC				5.5		323
4	2D 1H-13C HSQC				5.5		323
5	3D 1H-15N NOESY-HSQC				5.5		323
6	3D 1H-15N TOCSY-HSQC				5.5		323
7	3D HCCH-TOCSY				5.5		323
8	3D HNCA				5.5		323
9	3D HNHA				5.5		323
10	3D HNHB				5.5		323
11	2D VERSION OF A 4D 13C/15N HMQC-NOESY-HMQC				5.5		323
12	3D 13C F1-EDITED				5.5		323
13	F3-FILTERED HMQC-NOESY				5.5		323

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Varian	UNITY	600

NMR Refinement
Method	Details	Software
DISTANCE GEOMETRY/ SIMULATED ANNEALING	ALL STRUCTURE CALCULATIONS WERE PERFORMED USING X-PLOR VERSION 3.1. FIRST 60 MONOMER STRUCTURES WERE CALCULATED FROM INTRACHAIN DISTANCE RESTRAINTS, TOGETHER WITH THE DIHEDRAL ANGLE RESTRAINTS FOR PHI AND CHI1 AND THE HYDROGEN BOND RESTRAINTS, USING THE HYBRID DISTANCE GEOMETRY-DYNAMICAL SIMULATED ANNEALING METHOD (NILGES, M.; CLORE, G.M.; GRONENBORN, A.M. (1988); FEBS LETT. 229, 317-324). THE 30 BEST MONOMER STRUCTURES WERE USED AS INPUT FOR THE GENERATION OF TRIMER STARTING STRUCTURES. EACH SELECTED HELIX MONOMER WAS FIRST ORIENTED SUCH THAT ITS GEOMETRIC CENTER COINCIDED WITH THE ORIGIN AND ITS LONG AXIS LAY ALONG THE X-AXIS AND SECOND TRANSLATED BY 10 ANGSTROMS ALONG THE Y-AXIS. COORDINATES FOR THE SECOND AND THIRD SUBUNIT WERE GENERATED BY A ROTATION AROUND THE X-AXIS BY 120 OR 240 DEGREES, RESPECTIVELY. THE 30 GENERATED TRIMER STARTING STRUCTURES WERE USED AS INPUT FOR A SECOND RUN OF SIMULATED ANNEALING INCLUDING THE INTERCHAIN DISTANCE RESTRAINTS. IN THE RESULTING STRUCTURES THE INTERCHAIN DISULFIDE BONDS WERE INTRODUCED AND A FINAL RUN OF SIMULATED ANNEALING AND REFINEMENT PERFORMED. THE LAST STEPS OF REFINEMENT INCLUDED ADDITIONALLY NON-CRYSTALLOGRAPHIC SYMMETRY (NCS) CONSTRAINTS AND R^(-6)-SUM AVERAGED DISTANCE RESTRAINTS FOR AMBIGUOUS NOES (NILGES, M. (1993); PROTEINS 17, 297-309).	X-PLOR

NMR Ensemble Information
Conformer Selection Criteria	LOWEST ENERGY AND LEAST RESTRAINT VIOLATIONS
Conformers Calculated Total Number	30
Conformers Submitted Total Number	20

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	refinement	X-PLOR	3.1	BRUNGER
2	structure solution	X-PLOR	3.1

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.