3D2U

Structure of UL18, a Peptide-Binding Viral MHC Mimic, Bound to a Host Inhibitory Receptor

3D2U の概要

• エントリーDOI: 10.2210/pdb3d2u/pdb
• 分子名称: UL18 protein, Beta-2-microglobulin, Leukocyte immunoglobulin-like receptor subfamily B member 1, ... (9 entities in total)
• 機能のキーワード: mhc class i homolog, disease mutation, glycation, glycoprotein, immune response, immunoglobulin domain, mhc i, pyrrolidone carboxylic acid, secreted, membrane, phosphoprotein, receptor, transmembrane, immune system
• 由来する生物種: Human herpesvirus 5 (Human cytomegalovirus); 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 136348.39

構造登録者

Yang, Z.,Bjorkman, P.J. (登録日: 2008-05-08, 公開日: 2008-07-08, 最終更新日: 2024-11-20)

主引用文献

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

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: 18632577
DOI: 10.1073/pnas.0804551105

実験手法

X-RAY DIFFRACTION (2.21 Å)