Table 1.

NMR Structural Data and Refinement Statistics

NMR Structural Data and Refinement Statistics	LL2	HH2	HL2	LH2
Experimental restraints
distance restraints from ROEs/NOEs	48	68	67	77
dihedral angle restraints	10	8	6	9
H-bonding restraints	6	6	6	6
RMS deviations from experimental data
average distance restraint violation (Å)	0.048 ± 0.013	0.044 ± 0.012	0.032 ± 0.097	0.076 ± 0.007
distance restraint violations > 0.5 Å	0	0	0	0
average dihedral angle restraint violations	0.13 ± 0.14	0.21 ± 0.24	0.086 ± 0.075	0.231 ± 0.086
dihedral angle restraint violations > 5°	0 ± 0.00	0 ± 0.00	0 ± 0.00	0 ± 0.00
RMS deviations from ideal stereochemistry
bonds (Å)	0.0033 ± 0.0004	0.0038 ± 0.0004	0.0032 ± 0.0006	0.0051 ± 0.0051
angles (deg)	0.660 ± 0.029	0.771 ± 0.032	0.671 ± 0.028	0.866 ± 0.035
impropers (deg)	0.328 ± 0.057	0.10 ± 0.32	0.37 ± 0.12	0.770 ± 0.057
Ramachandran analysis of the structures*
residues in favored regions	3	2	2	1
residues in additionally allowed regions	3	2	3	4
residues in generously allowed regions	0	0	0	0
residues in disallowed regions	0	0	0	0
Lennard-Jones potential energies
after annealing (kcal·mol-1)	29.9 ± 9.7	11.2 ± 4.5	25.8 ± 4.0	65.6 ± 6.9
ensemble average (kcal·mol-1)	5.8 ± 6.1	−13 ± 11	−1.6 ± 6.7	43.9 ± 9.9
Coordinate precision (Å)
backbone	0.82 ± 0.32	0.35 ± 0.6	0.44 ± 0.21	0.41 ± 0.17
heavy atoms	1.64 ± 0.39	1.20 ± 0.27	1.35 ± 0.44	1.06 ± 0.23
sidechain precision, residues 1,8 **	2.5, 2.4	2.7, 1.1	2.2, 1.1	2.5, 1.3
No. of ensemble structures of 30 where sidechains 1& 8 are very close, close***	5, 1	0, 20	21, 9	6, 6

^*Hfl, Ati, and Pro residues not included in this analysis.

^**The coordinate precision of the heavy atoms in sidechains 1 & 8 respectively after annealing

^***H-H, H-F, or F-F distances between residues 1 and 8 that are “very close”(<3.6 Å apart), and “close” (between 3.6 Å and 5.3 Å apart).