Mutations in Gag associated with HLA-B*13. (A) Comparisons of numbers of variations from the consensus for p24 VQNLQGQMV (Gag residues 135 to 143; numbering corresponds to that for the HXB2 reference strain) with those for five residues beyond the N and C termini of the epitope. A total of 562 C clade RNA and DNA sequences were compared. Comparisons were also made for subjects not carrying B*57/5801. (B) Comparisons of numbers of variations from the consensus for p15 RQANFLGKI (Gag residues 429 to 437; numbering corresponds to that for the HXB2 reference strain) with those for five residues beyond the N and C termini of the epitope. A total of 347 C clade RNA and DNA sequences were compared. (C) Three epitopes restricted by B*13, B*1510, and B*57/5801 and their relations to the mutation at position 146, which is significantly associated with B*13, B*1510, and B*57/5801, and to the mutation at position 147, which is significantly associated with B*13 and B*57/5801 (shaded residues). +ve, positive; −ve, negative; WT, wild type.