Table 1.

Structural statistics

NMR spectroscopy data	〈SA〉	SABEST
rms deviations from NOE interproton distance restraints, Å*
All (1,852)	0.036  ± 0.002	0.039
Protein interresidue sequential (|i − j| = 1) (539)	0.037  ± 0.004	0.045
Protein interresidue short range (1 < |i − j ≤ 5) (287)	0.047  ± 0.006	0.043
Protein interresidue long range (|i − j| > 5) (627)	0.037  ± 0.002	0.040
Protein intraresidue (399)	0.028  ± 0.009	0.021
rms deviations from hydrogen bonding restraints, ņ (82)	0.028  ± 0.005	0.039
rms deviations of the dihedral angle restraints, deg‡ (195)	0.255  ± 0.085	0.312
rms deviations of the 3JHN coupling constants, Hz (58)	0.524  ± 0.038	0.573
Deviations from idealized covalent geometry
Bonds, Å	0.004  ± 0.0001	0.003
Angles, deg	0.450  ± 0.012	0.452
Impropers, deg	0.401  ± 0.023	0.389
Measures of structure quality
procheck-NMR (ref. 58)
Most ravored regions, %	66.4
Additionally allowed regions, %	31.2
Generously allowed regions, %	2.3
Disallowed regions, %	0.0
Coordinate precision, ŧ
Protein backbone	0.55  ± 0.11
All protein heavy atoms	1.12  ± 0.16

The notation of the NMR structures is as follows: 〈SA〉 are the final 25 simulated annealing structures; SA_BEST is the lowest energy structure within the ensemble. The number of terms for each restraint is given in parentheses. 

^*None of the structures exhibited distance violations greater than 0.5 Å, dihedral angle violations greater than 5°, or ³J_HNα coupling constant violations greater than 2 Hz. 

^† Two distance restraints were employed for each hydrogen bond. Hydrogen bond restraints were added at the very end of the refinement process based an analysis of the structures and amide solvent exchange data. 

^‡ 195 protein dihedral angle restraints (21 χ1 angles, 1 χ2 angle, 67 ψ, 106 φ). 

^§ The coordinate precision is defined as the average atomic rms deviation of the 25 individual SA structures and their mean coordinates. The values refer to residues K62 to V161 and K175 to V205.