Table 3. PISA inter-dimer interface analysis of T = 4 capsids1.
| Structure | Property | AA | BD | CB | DC |
|---|---|---|---|---|---|
| Reference | NRES | 46.6 | 49.4 | 38.8 | 38.2 |
| NHB | 3.8 | 4.4 | 2.8 | 1.8 | |
| NSB | 0.6 | 0.2 | 3.4 | 1.0 | |
| Area (Å2) | 729.2 | 730.9 | 562.16 | 537.8 | |
| ΔG (kCal/mol) | -12.08 | -11.96 | -7.92 | -8.06 | |
| V124 BSA (Å2) | 63 | 72 | 33 | 46 | |
| This study | NRES | 48 | 53 | 37 | 49 |
| NHB | 2 | 1 | 1 | 0 | |
| NSB | 6 | 1 | 4 | 0 | |
| Area (Å2) | 870.3 | 870.4 | 646.6 | 802.5 | |
| ΔG (kCal/mol) | -14.1 | -12.4 | -10.3 | -11.0 | |
| V124 BSA (Å2) | 65.3 | 61.3 | 36.4 | 63.2 |
1 Values in the upper half of the table are averages calculated from five reference structures: 1QGT, 2G33, 2G34, 2QIJ and 4G93. Values in the lower half of the table are from the T = 4 capsid described in this study. Here and throughout, interfaces are named with the first given chain fitting into the hydrophobic pocket of the second chain. Viewed from outside the lattice, the interfaces are named clockwise (Fig 2). NRES, NHB, and NSB are the numbers of residues, hydrogen bonds, and salt bridges, respectively. Free energies are derived from buried surface area. V124 BSA is the buried surface area of V124, a residue observed to be distinctly less buried during preliminary analysis of the reference structures, and also reported to change the T = 3:T = 4 ratio when mutated. Note that the CB interface has the lowest area and free energy values.