In order to differentiate between amino acids in different quasi 3-fold related subunits, their identity is defined as the amino acid sequence number in E1 + 2000, 3000, and 4000, and in E2 + 2500, 3500, and 4500 for positions #2, 3, and 4, respectively (see Figure 2). The surface is colored according to radial distance from the center of the VLP. The A, B, and D domains of E2 are bounded by a black, white and dashed white line, respectively. Residues in the putative receptor binding site on domain A of E2 are bounded by a yellow dashed line. The footprint of the Fabs onto the VLP surface is outlined in yellow.