Experiment: 1QP6

SOLUTION STRUCTURE OF ALPHA2D

SOLUTION NMR

NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D NOESY	2 MM ALPHA2D TRIS, PH 7.3, 25 C		52 mM	7.3	AMBIENT	298.0
2	DQF-COSY	2 MM ALPHA2D TRIS, PH 7.3, 25 C		52 mM	7.3	AMBIENT	298.0
3	E-COSY	2 MM ALPHA2D TRIS, PH 7.3, 25 C		52 mM	7.3	AMBIENT	298.0

NMR Spectrometer Information
Spectrometer	Manufacturer	Model	Field Strength
1	Bruker	AMX	600

NMR Refinement
Method	Details	Software
SIMULATED ANNEALING FOR 48 PS AT 2000K FOLLOWED BY A SLOW COOL TO 50K	STRUCTURE BASED ON 834 RESTRAINTS: 140 LONG-RANGE RESTRAINTS, 30 PHI ANGLE RESTRAINTS, AND 14 CHI-1 ANGLE RESTRAINTS. 83 OF THE LONG-RANGE NOES (59%) WERE DETERMINED TO ARISE FROM INTER-MONOMER CORRELATIONS BY COMPUTATIONAL METHODS. THE OTHER NOES WERE TREATED USING A WEIGHTING FUNCTION DEVELOPED FOR SYMMMETRIC HOMODIMERS THAT ALLOWS EACH NOE TO ARISE FROM EITHER AN INTRA- OR INTER- MONOMER CORRELATIONS AS DESCRIBED BY NILGES, M. PROTEINS (1993) 17:297- 309. SYMMETRY TERMS WERE EMPLOYED FOR C-ALPHA CARBONS ONLY. SEE JACS(1998)120: 1138-1145 FOR MORE DETAILS.	X-PLOR

NMR Ensemble Information
Conformer Selection Criteria	structures with the least restraint violations
Conformers Calculated Total Number	60
Conformers Submitted Total Number	16
Representative Model	11 (lowest energy)

Additional NMR Experimental Information
Details	THE STRUCTURE WAS DETERMINED USING 2D HOMONUCLEAR TECHNIQUES. BECAUSE ALPHA2D EXISTS AS A SYMMETRIC HOMODIMER, THERE EXISTS A PROBLEM OF DETERMINING WHETHER AN OBSERVED NOE ARISES FROM AN INTER- OR INTRA- MONOMER CORRELATION. THIS PROBLEM WAS DEALT WITH AS DESCRIBED REMARK 3.

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