Fig. 3. Seven- to eight-residue macrocycle NMR structures are very close to design models.

Columns A: Design model. B: Amino acid sequence, torsion bin string, hydrogen bond pattern, and building block composition. C: Observed backbone-backbone (green), backbone–side-chain (purple), and side-chain–side-chain (orange) NOEs. D: Overlay of design model (green) on MD-refined NMR ensemble (gray; the average backbone RMSD to the NMR ensemble is indicated). E: Average decrease in the propensity to favor the designed state (P_Near, see methods) over all mutations at each position. Darker gray indicates larger decreases (P_Near values for each substitution at each position are in fig. S16); positions particularly sensitive to mutation are boxed and indicated by color in the design model in column A. F: Representative energy funnels for mutations at key positions (colored points) as compared to the design sequence (gray points). Row I, column G: Experimental SLIM data. Distribution of peak width at half height for peptide libraries with all amino substitutions at positions 4 and 5; the position 4 library has a broader distribution consistent with the computed energy landscape in column F. Rows II, IV, V, column G: Representative energy landscapes for double substitutions (red) of critical residues overlaid on the original design landscape (gray). Row III, column G: Overlay of design model on alternative structure NMR ensemble (turn flip at bottom right).