title: Plasticity of human CD8αα binding to peptide-HLA-A*2402.
abstract: The human CD8 functions as a co-receptor for specific T cell recognition, and only one complex structure of human CD8αα binding to HLA-A*0201 has been solved, revealing the molecular basis of CD8 interacting with its ligand pHLA. Here, we present the complex structures of human CD8αα bound to HLA-A*2402, which demonstrate two opposite α3 domain CD loop shifts (either pull or push) in the HLA heavy chain upon CD8 engagement. Taking the previously reported mouse CD8-pMHC complex structures into account, from the structural view, all of the data indicate the plasticity of CD8 binding to pMHC/HLA, which facilitates its co-receptor function for T cells. The plasticity of CD8 binding appears not to affect the specificity of TCR recognition, as no peptide conformation change extends to the pMHC interface for TCR contacting.
authors.affiliation: CAS Key Laboratory of Pathogenic Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Shi
authors.forename: Jianxun
authors.initials: J
authors.lastname: Qi
authors.forename: Aikichi
authors.initials: A
authors.lastname: Iwamoto
authors.forename: George F
authors.initials: GF
authors.lastname: Gao
mesh_terms: D016827:CD8 Antigens / Q000737:chemistry* / Q000378:metabolism*; D015234:HLA-A Antigens / Q000737:chemistry* / Q000378:metabolism*; D059871:HLA-A24 Antigen; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D016827:CD8 Antigens; C409469:CD8 antigen, alpha chain; D015234:HLA-A Antigens; C438506:HLA-A*24:02 antigen; D059871:HLA-A24 Antigen