1BUQ

SOLUTION STRUCTURE OF DELTA-5-3-KETOSTEROID ISOMERASE COMPLEXED WITH THE STEROID 19-NORTESTOSTERONE-HEMISUCCINATE

SOLUTION NMR

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NMR Experiment
Experiment	Type	Sample Contents	Solvent	Ionic Strength	pH	Pressure	Temperature (K)	Spectrometer
1	2D NOESY			30 mM	7.2	1 atm	310
2	2D TOCSY			30 mM	7.2	1 atm	310
3	2D 1H-15N HSQC			30 mM	7.2	1 atm	310
4	2D 1H-13C CT-HSQC			30 mM	7.2	1 atm	310
5	3D 1H-13C-FILTERED NOESY-HSQC			30 mM	7.2	1 atm	310
6	3D 1H-15N TOCSY-HSQC			30 mM	7.2	1 atm	310
7	3D 1H-13C-NOESY-HSQC			30 mM	7.2	1 atm	310
8	3D 1H-15N HMQC-NOESY-HSQC			30 mM	7.2	1 atm	310
9	3D HCCH-TOCSY			30 mM	7.2	1 atm	310
10	3D 1H-13C HMQC-NOESY-HSQC			30 mM	7.2	1 atm	310
11	3D HNCO			30 mM	7.2	1 atm	310
12	3D HNCACB			30 mM	7.2	1 atm	310

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

NMR Refinement
Method	Details	Software
DISTANCE GEOMETRY, SIMULATED ANNEALING AND REFINEMENT CALCULATIONS	DURING THE REFINEMENT, THE NON-BONDED INTERACTIONS WERE MODELED ONLY BY A QUADRATIC REPULSIVE ENERGY TERM, WHILE THE ATTRACTIVE COMPONENT OF THE LENNARD- JONES POTENTIAL AND THE ELECTROSTATIC ENERGY WERE TURNED OFF. AT THE FINAL STAGES OF REFINEMENT, A SQUARE-WELL POTENTIAL ENERGY FUNCTION WAS USED FOR THE NOE AND THE DIHEDRAL ANGLE RESTRANTS WITH A FORCE OF 500 KCAL MOL-1 ANG-2 AND 200 KCAL MOL-1 RAD-2, RESPECTIVELY. OF THE 120 EMBEDDED SUBSTRUCTURES, 60 CONVERGED TO ACCEPTABLE STRUCTURES WITH NOE VIOLATION EQUAL OR LESS THAN 0.5ANG. OF THESE, 15 BEST STRUCTURES WITH NOE VIOLATIONS EQUAL OR LESS THAN 0.35 ANG AND DIHEDRAL VIOLATION < 5 DEG WERE SELECTED. MODEL 1 (STRUCTURE 1) OF THE 15 STRUCTURES OF THE KSI-19NTHS COMPLEX IS THE LOWEST ENERGY STRUCTURE.	X-PLOR

NMR Ensemble Information
Conformer Selection Criteria	NOE VIOLATION =< 0.35A AND DIHEDRAL VIOLATION < 5 DEG.
Conformers Calculated Total Number	120
Conformers Submitted Total Number	15
Representative Model	1 (n/a)

Additional NMR Experimental Information

Details

THE STRUCTURE OF THE 3-KETOSTEROID ISOMERASE 19-NORTESTOSTERONE HEMISUCCINATE ( 19-NTHS) COMPLEX WAS DETERMINED FROM BOTH 2D NOESY, 3D NOESY AND TRIPLE RESONANCE NMR SPECTRA ON AN UNLABELED SAMPLE (2D NOESY), 15N-LABELED, 13C-, 15N-UNIFORMLY LABELED, AND/OR 13C-,15N/15N-HETEROLABELED ISOMERASE WITH 1.1 MM 19-NTHS. 3D NOESY AND TRIPLE RESONACE SPECTRA ON THE 15N-UNIFORMLY LABELED AND 13C-,15N-UNIFORMLY SAMPLES WERE USED FOR 1H, 15N,13C ASSIGNMENTS AS WELL AS STRUCTURAL INFORMATION FOR EACH SUBUNIT. THE 1H-13C-FILTERED NOESY-HSQC OF A 13C, 15N/15N-HETEROLABELED SAMPLE PROVIDED CRITICAL NOES BETWEEN THE IDENTICAL MONOMERS OF THE HOMODIMER WHICH LED TO THE SOLUTION STRUCTURE OF KSI COMPLEXED TO 19-NTHS.

Computation: NMR Software
#	Classification	Version	Software Name	Author
1	refinement	X-PLOR	3.8	BRUNGER
2	structure solution	X-PLOR	3.8