3D2U
Structure of UL18, a Peptide-Binding Viral MHC Mimic, Bound to a Host Inhibitory Receptor
Summary for 3D2U
| Entry DOI | 10.2210/pdb3d2u/pdb |
| Descriptor | UL18 protein, Beta-2-microglobulin, Leukocyte immunoglobulin-like receptor subfamily B member 1, ... (9 entities in total) |
| Functional Keywords | mhc class i homolog, disease mutation, glycation, glycoprotein, immune response, immunoglobulin domain, mhc i, pyrrolidone carboxylic acid, secreted, membrane, phosphoprotein, receptor, transmembrane, immune system |
| Biological source | Human herpesvirus 5 (Human cytomegalovirus) More |
| Total number of polymer chains | 8 |
| Total formula weight | 136348.39 |
| Authors | Yang, Z.,Bjorkman, P.J. (deposition date: 2008-05-08, release date: 2008-07-08, Last modification date: 2024-11-20) |
| Primary citation | Yang, Z.,Bjorkman, P.J. Structure of UL18, a peptide-binding viral MHC mimic, bound to a host inhibitory receptor Proc.Natl.Acad.Sci.Usa, 105:10095-10100, 2008 Cited by PubMed Abstract: UL18 is a human cytomegalovirus class I MHC (MHCI) homolog that binds the host inhibitory receptor LIR-1 and the only known viral MHC homolog that presents peptides. The 2.2-A structure of a LIR-1/UL18/peptide complex reveals increased contacts and optimal surface complementarity in the LIR-1/UL18 interface compared with LIR/MHCI interfaces, resulting in a >1,000-fold higher affinity. Despite sharing only approximately 25% sequence identity, UL18's structure and peptide binding are surprisingly similar to host MHCI. The crystal structure suggests that most of the UL18 surface, except where LIR-1 and the host-derived light chain bind, is covered by carbohydrates attached to 13 potential N-glycosylation sites, thereby preventing access to bound peptide and association with most MHCI-binding proteins. The LIR-1/UL18 structure demonstrates how a viral protein evolves from its host ancestor to impede unwanted interactions while preserving and improving its receptor-binding site. PubMed: 18632577DOI: 10.1073/pnas.0804551105 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2.21 Å) |
Structure validation
Download full validation report
