On the Cover: Model of Ly-49C and H2K^b-OVA based on the crystal structure of Ly-49A-H-2D^d. Site 1 and site 2 interactions are shown. The H-2K^b H chain is yellow, ₂m is gray, the peptide is orange, the Ly-49C-1 subunit is blue, and Ly-49C-2 is light blue. Ly-49C mutated residues that affected MHC class I binding: N160D/T162K are shown in orange, I195/P196 are shown in green, and K225/I226 are shown in red. Mutated residues that did not affect the Ly-49C-H-2K^b interaction are shown as ball-and-stick molecules in backbone color. Ly-49C was threaded on the crystal structure of Ly-49A and was overlaid in the same orientation as Ly-49A in the Ly-49A-H-2D^d structure (pdb entry 1QO3). The crystal structure of H-2K^b-OVA (pdb entry 1VAC) was aligned with the ₁₂ domains of H-2D^d in the crystal. The modeling and image were prepared using the Swiss-PDB Viewer, and the image was refined with the Persistence of Vision Ray Tracer. (Figure 5 from Sundbäck, J., A. Achour, J. Michaëlsson, H. Lindström, and K. Kärre. NK cell inhibitory receptor Ly-49C residues involved in MHC class I binding. 793)