Figure 4.

Binding modes of CD8αα and CD8αβ isoforms with classical and non-classical MHC-I molecules. A summary of crystal structures of CD8 ectodomain/MHC-I complexes. From top left to bottom right: mouse CD8αβ/H-2D^d (PDB ID 3DMM), mouse CD8αα/H-2K^b (PDB ID 1BQH), mouse CDαα/TL (PDB ID 1NEZ), human CD8αα/HLA-A*02:01 (PDB ID 1AKJ), human CD8αα/HLA-A*24:02 (PDB ID 3QZW), human CD8αα/MR1 (PDB ID 7UMG), and chicken CD8αα/BF2*15:01 (PDB ID 6LHF). MHC heavy chains are colored green, β2m light chains colored cyan, antigens colored salmon, CD8α chains are colored magenta/light pink, and CD8β chains are colored yellow.