Table 1.

Structural Statistics for ARR10-B

Parameter{SA}<SA>r
X-PLOR energies (kcal·mol−1)a
Etotal 77.6 ± 3.275.8
Ebond 3.39 ± 0.273.46
Eangle 58.1 ± 1.358.3
Eimproper 6.49 ±0.345.97
Evdw 3.46 ± 0.994.04
Enoe 5.76 ± 0.843.70
Ecdih 0.46 ± 0.150.34
Root-mean-square deviation from    idealized geometry
Bond (Å)0.0018 ± 0.000070.0018
Angle (°) 0.44 ± 0.0050.44
Improper (°) 0.28 ± 0.010.27
Root-mean-square deviation from    experimental restraintsb
Distance (Å) 0.011 ± 0.00080.0091
Dihedral angle (°) 0.22 ± 0.040.19
Ramachandran plot analysis (%)c
Residues in most favored    regions92.8 (83.7)
Residues in additional      allowed regions6.4 (13.0)
Residues in generously allowed      regions0.8 (3.0)
Residues in disallowed regions0.0 (0.3)
Root-mean-square deviation from    mean structure (Å)d
Backbone (N, Cα, C′) atoms 0.72 ± 0.158
All nonhydrogen atoms 1.21 ± 0.164
• The notation of the NMR structures is as follows: {SA} is the ensemble of the final 15 simulated annealing structures; <SA>r is the restrained regularized mean structure obtained by averaging the backbone coordinates of the individual SA structures best fitted to each other (residues 188 to 239), followed by restrained regularization of the mean structure.

• a These values were estimated using X-PLOR 3.1. The final values of the force constants used for the calculations are as follows: 1000 kcal·mol−1·Å−2 for bond lengths, 500 kcal·mol−1·rad−2 for bond angles and improper torsions, 4 kcal·mol−1·Å−4 for the quartic van der Waals term with van der Waals radii set to 0.75 times the values used in the CHARMM empirical energy function, 50 kcal·mol−1·Å−2 for NOE-derived and hydrogen bonding distance restraints with the ceiling value of 1000 kcal·mol-1, and 200 kcal·mol-1·rad-2 for dihedral angle restraints.

• b None of the structures exhibited interproton distance violations > 0.5 Å or dihedral angle violations > 5°. The distance restraints comprise 402 intraresidue, 246 sequential (|i−j|= 1), 169 medium-range (1 < |i−j| < 5) and 76 long-range (|i−j| ≧ 5) NOEs. The dihedral angle restraints involve 49 ϕ, 51 ψ, 37 χ1, and 10 χ2.

• c The values were calculated for residues 188 to 239 using PROCHECK (Laskowski et al., 1996). The corresponding values calculated for all residues (179 to 242), are shown in parentheses.

• d The atomic root-mean-square deviation values were calculated for residues 188 to 239.