Fig 6.

Central slices through P124 (A) and P1247 (B) procapsids filtered to 15-Å resolution and oriented along the 2-fold icosahedral axis. The P124 procapsid exhibits additional density under the 5-fold vertex (arrow). Bars, 100 Å. (C) Inside view of the 5-fold vertex of the P1247 (gray mesh) and P124 (yellow) procapsids filtered to 8-Å resolution and depicted at a 3-sigma threshold. The P124 procapsid shows decreased density in the short helices at the tip of P1_A subunits at the 5-fold vertex (arrow). The additional density in the P124 procapsid (orange) has a similar size and shape to those of the short helix and may represent its alternative conformation in the absence of P7. Bar, 10 Å.