6LXW

Cryo-EM structure of human secretory immunoglobulin A in complex with the N-terminal domain of SpsA


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.27 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural insights into secretory immunoglobulin A and its interaction with a pneumococcal adhesin.

Wang, Y.Wang, G.Li, Y.Zhu, Q.Shen, H.Gao, N.Xiao, J.

(2020) Cell Res 30: 602-609

  • DOI: 10.1038/s41422-020-0336-3
  • Primary Citation of Related Structures:  
    6LX3, 6LXW

  • PubMed Abstract: 
  • Secretory Immunoglobulin A (SIgA) is the most abundant antibody at the mucosal surface. It possesses two additional subunits besides IgA: the joining chain (J-chain) and secretory component (SC). SC is the ectodomain of the polymeric immunoglobulin receptor (pIgR), which functions to transport IgA to the mucosa ...

    Secretory Immunoglobulin A (SIgA) is the most abundant antibody at the mucosal surface. It possesses two additional subunits besides IgA: the joining chain (J-chain) and secretory component (SC). SC is the ectodomain of the polymeric immunoglobulin receptor (pIgR), which functions to transport IgA to the mucosa. How the J-chain and pIgR/SC facilitate the assembly and secretion of SIgA remains incompletely understood. Furthermore, during the infection of Streptococcus pneumoniae, the pneumococcal adhesin SpsA hijacks pIgR/SC and SIgA to gain entry to human cells and evade host defense. How SpsA targets pIgR/SC and SIgA also remains elusive. Here we report a cryo-electron microscopy structure of the Fc region of IgA1 (Fcα) in complex with the J-chain and SC (Fcα-J-SC), which reveals the organization principle of SIgA. We also present a structure of Fcα-J-SC complexed with SpsA, which uncovers the specific interactions between SpsA and human pIgR/SC. These results advance the molecular understanding of SIgA and shed light on S. pneumoniae pathogenesis.


    Organizational Affiliation

    Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. junyuxiao@pku.edu.cn.



Macromolecules
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Interleukin-2,Immunoglobulin heavy constant alpha 1A, B, C, D291Homo sapiensMutation(s): 0 
Gene Names: IL2IGHA1
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Find proteins for P01876 (Homo sapiens)
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PHAROS:  P01876
Find proteins for P60568 (Homo sapiens)
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  • Reference Sequence
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Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
Immunoglobulin J chainE [auth J]167Homo sapiensMutation(s): 0 
Gene Names: JCHAINIGCJIGJ
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Find proteins for P01591 (Homo sapiens)
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PHAROS:  P01591
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
Polymeric immunoglobulin receptorF [auth P]573Homo sapiensMutation(s): 0 
Gene Names: PIGR
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Find proteins for P01833 (Homo sapiens)
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PHAROS:  P01833
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  • Reference Sequence
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Entity ID: 4
MoleculeChainsSequence LengthOrganismDetailsImage
SigA binding proteinG [auth S]317Streptococcus pneumoniaeMutation(s): 0 
Gene Names: spsA
UniProt
Find proteins for O33753 (Streptococcus pneumoniae)
Explore O33753 
Go to UniProtKB:  O33753
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.27 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Science Foundation (NSF, China)China--

Revision History  (Full details and data files)

  • Version 1.0: 2020-05-27
    Type: Initial release
  • Version 1.1: 2020-07-22
    Changes: Database references