FIGURE 8.

Three-dimensional model of a HLA-A2-β₂m-peptide complex with a C terminus-truncated HLA-A2 H chain. Backbone diagram of the HLA-A2-β₂m-HIVpol peptide complex (A) and the H chain-truncated HLA-A2-β₂m-HIVpol peptide complex (B) is shown. Blue, green, and red backbones indicate the HLA-A2 H chain, β₂m, and the HIVpol peptide, respectively. The models are generated by using the RasTop 1.3.1 molecular graphics program (P. Valadon) based on the coordinates retrieved from PDB ID 1AKJ (31). The coordinates corresponding to HLA-A2 H chain position 1∼209 (codon +24∼233) were used to generate the HLA-A2-β₂m-HIVpol peptide complex model with a truncated HLA-A2 H chain. Y209 indicates a tyrosine at position 209 (codon 233), which is the last residue before the missense codon-deduced residue leucine at position 210 (codon 234) in the 1259MEL HLA-A2 H chain. The red-dashed circles indicate the HLA-A2 α3 domain-β₂m contact area, which is postulated to be missing in the truncated version of HLA-A2-β₂m-HIVpol peptide complex.