Distribution of distances between amino acid substitutions in HA1 occurring on the same NGS± branches.

Abstract

<p>The distances in the three-dimensional structure of HA between amino acid substitutions occurring on the same NGS± branches were measured for (A) A/H3N2 and (B) A/H1N1 viruses. The red and black bars indicate the proportions of distances between pairs of charge+ and charge− substitutions and other pairs, respectively.</p