Consensus sequence alignment and CTL epitope prediction of GAG protein. GAG protein sequences deposited in GeneBank were aligned and consensus analyzed for the presence of HLA class I peptide-binding motifs by using the Epitope motif search facility at the HIV-Immunology Database. Amino acids with 100% identity were depicted as normal character, amino acid with >75% identity were reported in italics, amino acids with >50% identity were reported in bold, and amino acids with <50% identity were highlighted in grey. Gaps in the sequence represent amino acids of GAG protein present in less than 10% of the deposited sequences. Promiscuous HLA-class I epitope areas were underlined.