6UE7

Structure of dimeric sIgA complex

Summary for 6UE7

• Entry DOI: 10.2210/pdb6ue7/pdb
• EMDB information: 20749 20750 20751 20752
• Descriptor: Immunoglobulin heavy constant alpha 1, Polymeric immunoglobulin receptor, Immunoglobulin J chain, ... (6 entities in total)
• Functional Keywords: immunoglobulin, immune system
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 6
• Total formula weight: 190842.44

Authors

Kumar, N.,Arthur, C.P.,Ciferri, C.,Matsumoto, M.L. (deposition date: 2019-09-20, release date: 2020-02-19, Last modification date: 2024-10-16)

Primary citation

Kumar, N.,Arthur, C.P.,Ciferri, C.,Matsumoto, M.L.
Structure of the secretory immunoglobulin A core.
Science, 367:1008-1014, 2020

PubMed Abstract: Secretory immunoglobulin A (sIgA) represents the immune system's first line of defense against mucosal pathogens. IgAs are transported across the epithelium, as dimers and higher-order polymers, by the polymeric immunoglobulin receptor (pIgR). Upon reaching the luminal side, sIgAs mediate host protection and pathogen neutralization. In recent years, an increasing amount of attention has been given to IgA as a novel therapeutic antibody. However, despite extensive studies, sIgA structures have remained elusive. Here, we determine the atomic resolution structures of dimeric, tetrameric, and pentameric IgA-Fc linked by the joining chain (JC) and in complex with the secretory component of the pIgR. We suggest a mechanism in which the JC templates IgA oligomerization and imparts asymmetry for pIgR binding and transcytosis. This framework will inform the design of future IgA-based therapeutics.

PubMed: 32029686
DOI: 10.1126/science.aaz5807

Experimental method

ELECTRON MICROSCOPY (2.9 Å)