Different length peptides bind to HLA-Aw68 similarly at their ends but bulge out in the middle.
Guo, H.C., Jardetzky, T.S., Garrett, T.P., Lane, W.S., Strominger, J.L., Wiley, D.C.(1992) Nature 360: 364-366
- PubMed: 1448153 
- DOI: 10.1038/360364a0
- PubMed Abstract: 
We report here the determination and refinement to 1.9 A resolution by X-ray cryo-crystallography the structure of HLA-Aw68. The averaged image from the collection of bound, endogenous peptides clearly shows the atomic structure at the first three an ...