Fig. 2.

The structural relationship of m157 with classical and nonclassical MHC class I molecules. Ribbon diagrams of the 3D structures of m157 (A), H2-T22 (B) (13), and H2-K^b (C) (35) from the side and top views, showing the altered helical and β-strand topology of m157 in relation to nonclassical and classical MHC molecules. H2-T22 and H2-K^b are shown in association with the β₂m subunit [yellow (B) and orange (C)]. β-strands are numbered according to their order in the primary amino acid sequence (S1–S4) by domain, and helices are named according to their structural homology to that of the canonical MHC class I structure (12). All structural figures were generated with the program Pymol (36).