Table 3.
The occurrence and the fraction (shown in parentheses) of residue positions in different classes of conservation indices for the interfacial and noninterfacial surface region of the benchmark structures with sufficient homolog sequences
| Conservation index (CI) of group intervals | ||||
| <0.40 | 0.40–0.60 | 0.60–0.85 | >0.85 | |
| Nonantigen–antibody complexes | ||||
| Noninterfacial surface residues | 3266 (0.42) | 2058 (0.26) | 1497 (0.19) | 1009 (0.13) |
| Interfacial surface residues | 405 (0.35) | 253 (0.22) | 259 (0.23) | 225 (0.20) |
| Ratio | 0.85 | 0.84 | 1.19 | 1.53 |
| Antigen–antibody complexes | ||||
| Noninterfacial surface residues | 1128 (0.16) | 2154 (0.31) | 2169 (0.31) | 1440 (0.21) |
| Interfacial surface residues | 282 (0.49) | 147 (0.25) | 106 (0.18) | 43 (0.07) |
| Ratio | 2.98 | 0.81 | 0.58 | 0.36 |
| Only antibody regions | ||||
| Noninterfacial surface residues | 860 (0.17) | 1729 (0.34) | 1700 (0.34) | 761 (0.15) |
| Interfacial surface residues | 196 (0.61) | 73 (0.23) | 43 (0.13) | 9 (0.03) |
| Ratio | 3.59 | 0.66 | 0.40 | 0.19 |
| Only antigen regions | ||||
| Noninterfacial surface residues | 268 (0.15) | 425 (0.23) | 469 (0.25) | 679 (0.37) |
| Interfacial surface residues | 86 (0.33) | 74 (0.29) | 63 (0.25) | 34 (0.13) |
| Ratio | 2.30 | 1.27 | 0.96 | 0.36 |
Solvent accessibility >10% is used as the cutoff to define a residue as surface residue.