7JG2

Secretory Immunoglobin A (SIgA)

7JG2 の概要

• エントリーDOI: 10.2210/pdb7jg2/pdb
• 関連するPDBエントリー: 7JG1
• EMDBエントリー: 22309 22310
• 分子名称: Igh protein, Polymeric immunoglobulin receptor, Immunoglobulin J chain, ... (7 entities in total)
• 機能のキーワード: immune system
• 由来する生物種: Mus musculus (Mouse); 詳細
• タンパク質・核酸の鎖数: 6
• 化学式量合計: 232033.27

構造登録者

Kumar Bharathkar, S.,Parker, B.P.,Malyutin, A.G.,Stadtmueller, B.M. (登録日: 2020-07-18, 公開日: 2020-11-11, 最終更新日: 2025-05-21)

主引用文献

Kumar Bharathkar, S.,Parker, B.W.,Malyutin, A.G.,Haloi, N.,Huey-Tubman, K.E.,Tajkhorshid, E.,Stadtmueller, B.
The structures of Secretory and dimeric Immunoglobulin A.
Elife, 9:-, 2020

PubMed Abstract: Secretory (S) Immunoglobulin (Ig) A is the predominant mucosal antibody, which binds pathogens and commensal microbes. SIgA is a polymeric antibody, typically containing two copies of IgA that assemble with one joining-chain (JC) to form dimeric (d) IgA that is bound by the polymeric Ig-receptor ectodomain, called secretory component (SC). Here, we report the cryo-electron microscopy structures of murine SIgA and dIgA. Structures reveal two IgAs conjoined through four heavy-chain tailpieces and the JC that together form a β-sandwich-like fold. The two IgAs are bent and tilted with respect to each other, forming distinct concave and convex surfaces. In SIgA, SC is bound to one face, asymmetrically contacting both IgAs and JC. The bent and tilted arrangement of complex components limits the possible positions of both sets of antigen-binding fragments (Fabs) and preserves steric accessibility to receptor-binding sites, likely influencing antigen binding and effector functions.

PubMed: 33107820
DOI: 10.7554/eLife.56098

実験手法

ELECTRON MICROSCOPY (3.3 Å)