7ZQI

MHC class I from a wild bird in complex with a nonameric peptide P2

7ZQI の概要

• エントリーDOI: 10.2210/pdb7zqi/pdb
• 分子名称: MHC class I antigen, Beta-2-microglobulin, Inosine monophosphate dehydrogenase-related protein, ... (7 entities in total)
• 機能のキーワード: major histocompatibility complex class i, acrocephalus arundinaceus, antigen presentation, cell-surface receptor, nonameric peptide from vibrio, immune system
• 由来する生物種: Acrocephalus arundinaceus (great reed warbler); 詳細
• タンパク質・核酸の鎖数: 3
• 化学式量合計: 47087.26

構造登録者

Eltschkner, S.,Mellinger, S.,Buus, S.,Nielsen, M.,Paulsson, K.M.,Lindkvist-Petersson, K.,Westerdahl, H. (登録日: 2022-04-29, 公開日: 2023-05-10, 最終更新日: 2024-10-23)

主引用文献

Eltschkner, S.,Mellinger, S.,Buus, S.,Nielsen, M.,Paulsson, K.M.,Lindkvist-Petersson, K.,Westerdahl, H.
The structure of songbird MHC class I reveals antigen binding that is flexible at the N-terminus and static at the C-terminus.
Front Immunol, 14:1209059-1209059, 2023

PubMed Abstract: Long-distance migratory animals such as birds and bats have evolved to withstand selection imposed by pathogens across the globe, and pathogen richness is known to be particularly high in tropical regions. Immune genes, so-called Major Histocompatibility Complex (MHC) genes, are highly duplicated in songbirds compared to other vertebrates, and this high MHC diversity has been hypothesised to result in a unique adaptive immunity. To understand the rationale behind the evolution of the high MHC genetic diversity in songbirds, we determined the structural properties of an MHC class I protein, Acar3, from a long-distance migratory songbird, the great reed warbler (in short: ). The structure of Acar3 was studied in complex with pathogen-derived antigens and shows an overall antigen presentation similar to human MHC class I. However, the peptides bound to Acar3 display an unusual conformation: Whereas the N-terminal ends of the peptides display enhanced flexibility, the conformation of their C-terminal halves is rather static. This uncommon peptide-binding mode in Acar3 is facilitated by a central Arg residue within the peptide-binding groove that fixes the backbone of the peptide at its central position, and potentially permits successful interactions between MHC class I and innate immune receptors. Our study highlights the importance of investigating the immune system of wild animals, such as birds and bats, to uncover unique immune mechanisms which may neither exist in humans nor in model organisms.

PubMed: 37483599
DOI: 10.3389/fimmu.2023.1209059

実験手法

X-RAY DIFFRACTION (2.15 Å)