Figure 3.

The VP structure of CnMV, PBoV1, and RBoV. (a) Amino acid residues modeled for the βD strand are shown inside their density maps at a sigma (σ) threshold of 2.5 (in black). The amino acid residues are labeled and shown as stick representations and colored according to atom type: C = yellow, O = red, N = blue, S = green. These images were generated using UCSF-Chimera [35]. (b) The VP structures are shown as ribbon diagrams inside transparent surface representations. The secondary structure elements (α-helices in red, β-strands in gray), the N- and C-termini, and variable regions (VRs) are labeled.