FIG. 3.

Variability in the HVR1 neutralization epitope. (A) Amino acid (aa) variations among 1,382 isolates of different genotypes and subtypes extracted from DataBank (40). The first line represents the consensus sequence. (B) Amino acids are listed in decreasing order of observed frequency, from top to bottom. Uppercase letters represent amino acids with a >10% presence; bold lowercase letters represent amino acids found only in the Egyptian isolates of this study. The arrows indicate the residues essential for the anchoring of the E2 glycoprotein core and in maintaining the HVR1 conformation.