Figure 2.

Physicochemical properties of interface residues in the c_mono, c_{mono_in_multi}, and c_multi binding classes. (A) Examples of c_mono (left), c_{mono_in_multi} (middle), and c_multi (right) interfaces. The residues involved in each interface are color-mapped onto the surface in cyan (c_mono), blue (c_{mono_in_multi}), and orange (c_multi). Selected partners are represented as cartoon. Left: PDB ID 1x8d, chains D/C. Middle: PDB ID 1pp9, chains S/B. Right: PDB ID 1b6c, chains E/F. (B–E) Different types of calculated propensities relative to the surface of c_mono (cyan), c_{mono_in_multi} (blue), and c_multi (orange) residues of S^Full. Error bars and significance levels were estimated with bootstrap resampling. Stars are drawn above c_{mono_in_multi} and c_multi distributions, indicating the significance levels (*** p-value <0.001, ** 0.001 ≤ p-value <0.01, * 0.01 ≤ p-value <0.05) of the comparison with c_mono (cyan) and c_{mono_in_multi} (blue). (B) Amino acid propensity P_aa. (C) Conservation propensity P_cons. The conservation is expressed as ConSurf conservation grade (G_cons, ranging from 1, less conserved, to 9, most conserved). (D) DSSP secondary structure (SS) propensity P_SS. The three SS groups collect positions annotated as helix (H = “H” + “G” + “I” in the DSSP dictionary), strand (E = “E” + “B”) and loop (L = blank + “S” + “T”). (E) Relative solvent accessibility (SASA^r) propensity P_SASA^r. Three levels of SASA^r are considered, with SASA^r < 20%, 20% ≤ SASA^r < 50%, and SASA^r ≥ 50%. (F) Fraction of S^Full interface residues with a small (<20%), medium (20–50%) or large (≥50%) normalized buried SASA (ΔSASAⁿ). The maximum ΔSASAⁿ value is used for residues involved in more than one complex. (G) Standardized hydration score S_hyd in the S^MD binding classes.