Table I.

Structural Statistics and Atomic rms Differences^a

A. Structural Statistics
			<SA>	( $\overline{\text{SA}}$)r
rms deviations from experimental distance restraints (Å)
all (1410)			0.032 ± 0.035	0.022
interresidue sequential (|i−j| = 1) (524)			0.029 ± 0.005	0.024
interresidue short range (1 <|i−j| # 5) (662)			0.023 ± 0.003	0.023
interresidue long-range (|i−j| > 5) (124)			0.011 ± 0.008	0.0
H-bonds (100)b			0.031 ± 0.006	0.029
rms deviation from exptl dihedral restraints (deg) (167)c,d			0.184 ± 0.160	0.301
rms deviation from exptl Cα restraints (ppm) (82)			0.89 ± 0.01	0.90
rms deviation from exptl Cβ restraints (ppm) (80)			0.76 ± 0.03	0.70
rms deviation from 3JNHα restraints (Hz) (50)			0.87 ± 0.07	0.62
FNOE (kcal mol−1)d			50 ± 11	39
Ftor (kcal mol−1)d			1.10 ± 0.61	0.93
Frepel (kcal mol−1)e			−135 ± 22	−125
FL-J (kcal mol−1)f			−3102 ± 111	−3194
deviations from idealized covalent geometry
bonds (Å) (1500)			0.004 ± 0	0.005
angles (deg) (2730)			0.666 ± 0.029	0.792
impropers (deg) (756)g			0.639 ± 0.034	0.666
PROCHECKh
Overall G-Factor			0.28 ± 0.04	0.24
% Residues in most favorable region of Ramachandran plot			95.1 ± 2.0	97.5
H-bond energy			0.95 ± 0.08	0.50
Number of bad contacts/100 residues			0.2 ± 0.6	0.0
B. Atomic rms Differences (Å)
	Residues 1–45		secondary structurei
	backbone atoms	all atoms	backbone atoms	all atoms
<SA> vs SA	0.62 ± 0.17	1.20 ± 0.19	0.65 ± 0.18	1.20 ± 0.20
<SA> vs (SA)r	0.65 ± 0.17	1.29 ± 0.21	0.68 ± 0.19	1.29 ± 0.22
(SA)r vs $\overline{\text{SA}}$	0.19	0.49	0.22	0.48

^aThe notation of the structures is as follows: <SA> are the final 30 simulated annealing structures; $\overline{\text{SA}}$ is the mean structure obtained by averaging the coordinates of the individual SA structures best fit to each other; and ( $\overline{\text{SA}}$)_r is the restrained minimized mean structure obtained by restrained minimization of the mean structure $\overline{\text{SA}}$ (57). The number of terms for the various restraints is given in parentheses.

^bFor backbone NH-CO hydrogen bond there are two restraints: rNH-O = 1.5–2.3 Å and rN-O = 2.5 – 3.3 Å. All hydrogen bonds involve slowly exchanging NH protons.

^cThe torsion angle restraints comprise 84 φ and 83ψ.

^dThe values of the square-well NOE (F_NOE) and torsion angle (F_tor) potentials (cf. eqs 2 and 3 in (58)) are calculated with force constants of 50 kcal mol ⁻¹ Å⁻² and 200 kcal mol⁻¹ rad⁻², respectively.

^eThe value of the quartic van der Waals repulsion term (Frep) (cf. eq 5 in (59)) is calculated with a force constant of 4 kcal mol ⁻¹ Å⁻⁴ with the hard-sphere van der Waals radius set to 0.9 times the standard values used in the CHARMM (60) empirical energy function (57,61,62).

^fEL-J is the Lennard-Jones-van der Waals energy calculated with the CHARMM empirical energy function.

^gThe improper torsion restraints serve to maintain planarity and chirality.

^hThese were calculated using the PROCHECK program.

ⁱThe residues in the regular secondary structure are: 12–24 (α1), 30–45 (α2), 3–10 (β1).