Primary Citation of Related Structures:   1HSA
PubMed Abstract: 
Cell surface complexes of class I MHC molecules and bound peptide antigens serve as specific recognition elements controlling the cytotoxic immune response. The 2.1 A structure of the human class I MHC molecule HLA-B27 provides a detailed composite image of a co-crystallized collection of HLA-B27-bound peptides, indicating that they share a common main-chain structure and length ...
Cell surface complexes of class I MHC molecules and bound peptide antigens serve as specific recognition elements controlling the cytotoxic immune response. The 2.1 A structure of the human class I MHC molecule HLA-B27 provides a detailed composite image of a co-crystallized collection of HLA-B27-bound peptides, indicating that they share a common main-chain structure and length. It also permits direct visualization of the conservation of arginine as an "anchor" side chain at the second peptide position, which is bound in a potentially HLA-B27-specific pocket and may therefore have a role in the association of HLA-B27 with several diseases. Tight peptide binding to class I MHC molecules appears to result from the extensive contacts found at the ends of the cleft between peptide main-chain atoms and conserved MHC side chains, which also involve the peptide in stabilizing the three-dimensional fold of HLA-B27. The concentration of binding interactions at the peptide termini permits extensive sequence (and probably some length) variability in the center of the peptide, where it is exposed for T cell recognition.
Related Citations: 
The Structure of Hla-B27 Reveals Nonamer Self-Peptides Bound in an Extended Conformation Madden, D.R., Gorga, J.C., Strominger, J.L., Wiley, D.C. (1991) Nature 353: 321
Identification of Self Peptides Bound to Purified Hla-B27 Jardetzky, T.S., Lane, W.S., Robinson, R.A., Madden, D.R., Wiley, D.C. (1991) Nature 353: 326
Crystallization and Preliminary X-Ray Diffraction Studies of the Human Major Histocompatibility Antigen Hla-B27 Gorga, J.C., Madden, D.R., Prendergast, J.K., Wiley, D.C., Strominger, J.L. (1992) Proteins 12: 87
Refined Structure of the Human Histocompatibility Antigen Hla-A2 at 2.6 Angstroms Resolution Saper, M.A., Bjorkman, P.J., Wiley, D.C. (1991) J Mol Biol 219: 277
Specificity Pockets for the Side Chains of Peptide Antigens in Hla-Aw68 Garrett, T.P.J., Saper, M.A., Bjorkman, P.J., Strominger, J.L., Wiley, D.C. (1989) Nature 342: 692
Structure of the Human Class I Histocompatibility Antigen, Hla-A2 Bjorkman, P.J., Saper, M.A., Samraoui, B., Bennett, W.S., Strominger, J.L., Wiley, D.C. (1987) Nature 329: 506
The Foreign Antigen Binding Site and T Cell Recognition Regions of Class I Histocompatibility Antigens Bjorkman, P.J., Saper, M.A., Samraoui, B., Bennett, W.S., Strominger, J.L., Wiley, D.C. (1987) Nature 329: 512
Crystallization and X-Ray Diffraction Studies on the Histocompatibility Antigens Hla-A2 and Hla-A28 from Human Cell Membranes Bjorkman, P.J., Strominger, J.L., Wiley, D.C. (1985) J Mol Biol 186: 205
Organizational Affiliation: 
Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.