Table 1.
NMR and refinement statistics for protein structures
| pH 7.5 | pH 4.5 | |
|---|---|---|
| NMR distance and dihedral constraints | ||
| Distance constraints | ||
| Total NOE | 229 × 4 | 218 × 4 |
| Intraresidue | 0 × 4 | 0 × 4 |
| Inter-residue | 229 × 4 | 218 × 4 |
| Sequential (|i − j| = 1) | 98 × 4 | 90 × 4 |
| Medium range (2 ≤ |i − j| ≤ 4) | 68 × 4 | 63 × 4 |
| Long range (|i − j| ≥ 5) | 0 × 4 | 1 × 4 |
| Intermolecular | 25 × 4 | 26 × 4 |
| Hydrogen bonds | 38 × 4 | 38 × 4 |
| Total dihedral-angle restraints | ||
| ϕ | 26 × 4 | 29 × 4 |
| ψ | 26 × 4 | 29 × 4 |
| Total orientation constraints | 10 × 4 | 10 × 4 |
| 1H-15N dipolar couplings | 10 × 4 | 10 × 4 |
| Violations (mean ± s.d.) | ||
| Distance constraints (Å) | 0.06 ± 0.01 | 0.09 ± 0.01 |
| Dihedral-angle constraints (°) | 0.18 ± 0.22 | 0.32 ± 0.24 |
| Max. dihedral-angle violation (°) | 5.16 | 6.28 |
| Max. distance-constraint violation (Å) | 0.61 | 0.56 |
| Deviations from idealized geometry | ||
| Bond lengths (Å) | 0.002 ± 0.000 | 0.002 ± 0.000 |
| Bond angles (°) | 0.40 ± 0.03 | 0.39 ± 0.01 |
| Impropers (°) | 0.34 ± 0.03 | 0.35 ± 0.02 |
| Average pairwise r.m.s. deviation (Å)a | ||
| Heavy | 1.43 ± 0.25 | 1.46 ± 0.34 |
| Backbone | 0.71 ± 0.17 | 0.85 ± 0.30 |
a
Pairwise r.m.s.d. was calculated among 10 lowest-energy refined structures.