Fig. 3. : analysis of the human respiratory syncytial virus (HRSV) G protein. (A) Maximum likelihood unrooted tree based on the JTT + G model. The bootstrap value is shown next to the branch (only greater than 50). The tree is drawn to scale, and the branch lengths are measured as the number of substitutions per site. The analysis involved 32 HRSV amino acid (aa) sequences, which are identified by their genotype followed by their GenBank accession number. (B) Mean aa divergence (based on p-distance) found between the major clades HRSV-A and HRSV-B. The mean aa divergence found within the groups is shown in bold.