Table S1.
NMR and structure statistics
| Protein or protein complex | FliT | FliTΔα4–FliDC | FliTΔα4–FliIEN |
| Completeness of resonance assignments* | |||
| Backbone, % | 70 | 95 | 95 |
| Methyl groups, % | 97 | 100 | 100 |
| Aromatic, % | 100 | 100 | 97 |
| Conformationally restricting restraints† | |||
| NOE | 427 | 1243 | 1114 |
| Short, |i − j| ≤ 1 | 148 | 490 | 373 |
| Medium range, 2 < |i − j| < 5 | 154 | 429 | 327 |
| Long range, |i − j| ≥ 5 | 125 | 324 | 414 |
| NOE restraints per residue | 3.8 | 8.8 | 10.6 |
| Interchain NOEs‡ | n/a | 166 | 169 |
| Hydrogen bond, long range, |i − j| ≥ 5 | 138 (0) | 212 (3) | 180 (6) |
| Dihedral angle | 170 | 289 | 214 |
| Total restraints, long range, |i − j| ≥ 5 | 735 (125) | 1,744 (282) | 1,508 (420) |
| Restraints per residue, total/long range | 6.5/1.1 | 12.4/2.3 | 14.4/4.0 |
| Residual distance restraint violations† | |||
| Average restraint violations/structure | |||
| 0.1–0.2 Å | 5.9 | 6.5 | 12.5 |
| 0.2–0.5 Å | 3.8 | 0.2 | 1.5 |
| >0.5 Å | 0.0 | 0.0 | 0.0 |
| Average rms violation/restraint, Å | 0.05 | 0.01 | 0.02 |
| Maximum distance violation, Å | 0.43 | 0.34 | 0.34 |
| Model quality† | |||
| Rmsd from average coordinates, Å | |||
| All backbone atoms, ordered/all | 0.5/1.9 | 0.5/0.5 | 0.5/1.2 |
| All heavy atoms, ordered/all | 0.9/2.1 | 0.7/0.7 | 0.9/1.6 |
| Rmsd bond lengths, Å | 0.05 | 0.019 | 0.019 |
| Rmsd bond angles, degrees | 1.1 | 1.1 | 1.1 |
| MolProbity Ramachandran plot§ | |||
| Most favored regions, 95.9% | 94.3 | 95.9 | 97.5 |
| Additionally allowed regions, % | 4.5 | 3.4 | 2.5 |
| Disallowed regions, % | 0.1 | 0.6 | 0.0 |
| Global quality scores (raw/Z-score)† | |||
| Verify3D | 0.36/1.73 | 0.36/−1.61 | 0.33/−2.09 |
| ProsaII | 0.20/1.18 | 0.80/0.62 | 0.77/0.50 |
| Procheck G-factor, ϕ/ψ§ | 0.34/−1.93 | 0.29/1.46 | 0.42/1.97 |
| Procheck G-factor, all dihedrals§ | 0.64/−0.04 | 0.11/0.65 | 0.21/1.24 |
| MolProbity clashscore | 20.94/−2.07 | 17.74/−1.52 | 16.11/−1.24 |
| Buried surface area in the complex¶ | |||
| Total/hydrophobic/polar, Å2 | n/a | 2,586.3/2,231.1/355.1 | 2,231.4/1,821.2/410.4 |
| Solvation-free energy gain/interface specificity/shape complementarity factor# | |||
| ΔiG, kcal/mol/P value/Sc | n/a | −32.8/0.028/0.718 | −24.5/0.130/0.642 |
Structural statistics were computed for the ensemble of 20 deposited structures.
Computed for each protein/complex (residues): full-length FliT (1A–122A), FliT (1A–95A):FliD (428B–467B), and FliT (1A–95A):FliI (1B–25B). Observable resonances consistent with U-[2H,15N,13C] and selective CH3 and aromatic labeling are included: Cα, Cβ, C′ (backbone), Ala(β), Ile(δ1), Leu(δ1,2), Met(ε), Thr(γ2), Val(γ1,2) (methyls), and U-[1H,13C]-Phe,Tyr, and Trp (aromatic).
Calculated for protein using the PSVS 1.5 program (1). Average distance constraints were calculated using the sum of r−6.
Interchain contacts for FliT:FliD and FliT:FliI complexes.
Ordered residue ranges [S(ϕ) + S(ψ) > 1.8] for FliT (1–122): 2–55, 58–82, 98–115. Secondary structure elements: 2–26 (α1), 30–48 (α2), 58–83 (α3), and 97–111 (α4). Ordered residue ranges [S(ϕ) + S(ψ) > 1.8] for FliT (1A–95A):FliD (428B–467B): 1–50, 53–95 (chain A), 428–466 (chain B). Secondary structure elements (chain A): 2–27 (α1), 30–48 (α2), 58–94 (α3). Secondary structure elements (chain B): 428–466 (α1). Ordered residue ranges [S(ϕ) + S(ψ) > 1.8] for FliT (1A–95A):FliI (1B–25B): 2–93 (chain A), 1–23 (chain B). Secondary structure elements (chain A): 2–27 (α1), 31–48 (α2), 58–93 (α3). Secondary structure elements (chain B): 2–20 (α1).
Calculated with NACCESS 2.1.1.
Computed with ePISA 1.51 and CCP4 6.5.