3kyo
Crystal structure of HLA-G presenting KLPAQFYIL peptide
Structural highlights
FunctionHLAG_HUMAN Involved in the presentation of foreign antigens to the immune system. Plays a role in maternal tolerance of the fetus by mediating protection from the deleterious effects of natural killer cells, cytotoxic T-lymphocytes, macrophages and mononuclear cells. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe highly polymorphic major histocompatibility complex class Ia (MHC-Ia) molecules present a broad array of peptides to the clonotypically diverse alphabeta T-cell receptors. In contrast, MHC-Ib molecules exhibit limited polymorphism and bind a more restricted peptide repertoire, in keeping with their major role in innate immunity. Nevertheless, some MHC-Ib molecules do play a role in adaptive immunity. While human leukocyte antigen E (HLA-E), the MHC-Ib molecule, binds a very restricted repertoire of peptides, the peptide binding preferences of HLA-G, the class Ib molecule, are less stringent, although the basis by which HLA-G can bind various peptides is unclear. To investigate how HLA-G can accommodate different peptides, we compared the structure of HLA-G bound to three naturally abundant self-peptides (RIIPRHLQL, KGPPAALTL and KLPQAFYIL) and their thermal stabilities. The conformation of HLA-G(KGPPAALTL) was very similar to that of the HLA-G(RIIPRHLQL) structure. However, the structure of HLA-G(KLPQAFYIL) not only differed in the conformation of the bound peptide but also caused a small shift in the alpha2 helix of HLA-G. Furthermore, the relative stability of HLA-G was observed to be dependent on the nature of the bound peptide. These peptide-dependent effects on the substructure of the monomorphic HLA-G are likely to impact on its recognition by receptors of both innate and adaptive immune systems. The structure and stability of the monomorphic HLA-G are influenced by the nature of the bound peptide.,Walpole NG, Kjer-Nielsen L, Kostenko L, McCluskey J, Brooks AG, Rossjohn J, Clements CS J Mol Biol. 2010 Mar 26;397(2):467-80. Epub 2010 Feb 1. PMID:20122941[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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