FIG. 3.

Multiple alignment of the amino acid sequences of the C2V3 region. The C2V3 amino acid sequences were aligned by comparison with the consensus sequence within each mother-child pair. Dots indicate the identity with the consensus sequence for each pair, dashes are amino acid deletions, and “x” indicates a stop codon. The charges of the V3 loop amino acids and frequencies of clones with identical amino acid sequences are indicated at the end of each sequence. Sequences containing amino acid distributions compatible with the SI phenotype are indicated by an asterisk. Potential N-linked glycosylation sites are indicated by underlined letters.