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Open data
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Basic information
Entry | Database: PDB / ID: 6lx3 | ||||||
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Title | Cryo-EM structure of human secretory immunoglobulin A | ||||||
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![]() | IMMUNE SYSTEM / immunoglobulin / dimer / transcytosis / secreted | ||||||
Function / homology | ![]() polymeric immunoglobulin receptor activity / immunoglobulin transcytosis in epithelial cells mediated by polymeric immunoglobulin receptor / kappa-type opioid receptor binding / dimeric IgA immunoglobulin complex / regulation of CD4-positive, alpha-beta T cell proliferation / regulation of T cell homeostatic proliferation / polymeric immunoglobulin binding / interleukin-2 receptor binding / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex ...polymeric immunoglobulin receptor activity / immunoglobulin transcytosis in epithelial cells mediated by polymeric immunoglobulin receptor / kappa-type opioid receptor binding / dimeric IgA immunoglobulin complex / regulation of CD4-positive, alpha-beta T cell proliferation / regulation of T cell homeostatic proliferation / polymeric immunoglobulin binding / interleukin-2 receptor binding / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex / monomeric IgA immunoglobulin complex / secretory IgA immunoglobulin complex / response to tacrolimus / positive regulation of plasma cell differentiation / glycosphingolipid binding / negative regulation of lymphocyte proliferation / Fc receptor signaling pathway / negative regulation of T-helper 17 cell differentiation / IgA binding / positive regulation of tissue remodeling / glomerular filtration / RUNX1 and FOXP3 control the development of regulatory T lymphocytes (Tregs) / detection of chemical stimulus involved in sensory perception of bitter taste / IgA immunoglobulin complex / leukocyte activation involved in immune response / positive regulation of isotype switching to IgG isotypes / interleukin-2-mediated signaling pathway / activated T cell proliferation / natural killer cell activation / kinase activator activity / positive regulation of regulatory T cell differentiation / : / negative regulation of B cell apoptotic process / IgG immunoglobulin complex / Interleukin-2 signaling / positive regulation of immunoglobulin production / azurophil granule membrane / positive regulation of dendritic spine development / receptor clustering / positive regulation of activated T cell proliferation / positive regulation of respiratory burst / positive regulation of interleukin-17 production / humoral immune response / T cell differentiation / Interleukin receptor SHC signaling / Scavenging of heme from plasma / immunoglobulin complex, circulating / immunoglobulin receptor binding / positive regulation of B cell proliferation / extrinsic apoptotic signaling pathway in absence of ligand / positive regulation of tyrosine phosphorylation of STAT protein / complement activation, classical pathway / negative regulation of protein phosphorylation / cytokine activity / antigen binding / Cell surface interactions at the vascular wall / B cell receptor signaling pathway / growth factor activity / epidermal growth factor receptor signaling pathway / negative regulation of inflammatory response / positive regulation of inflammatory response / positive regulation of type II interferon production / cell-cell signaling / protein-macromolecule adaptor activity / antibacterial humoral response / positive regulation of cytosolic calcium ion concentration / RAF/MAP kinase cascade / positive regulation of cell growth / carbohydrate binding / protein-containing complex assembly / response to ethanol / adaptive immune response / transcription by RNA polymerase II / blood microparticle / receptor complex / cell adhesion / immune response / innate immune response / positive regulation of cell population proliferation / Neutrophil degranulation / negative regulation of apoptotic process / protein homodimerization activity / positive regulation of transcription by RNA polymerase II / extracellular space / extracellular exosome / extracellular region / plasma membrane Similarity search - Function | ||||||
Biological species | ![]() | ||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.15 Å | ||||||
![]() | Wang, Y. / Wang, G. / Li, Y. / Xiao, J. | ||||||
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![]() | ![]() Title: Structural insights into secretory immunoglobulin A and its interaction with a pneumococcal adhesin. Authors: Yuxin Wang / Guopeng Wang / Yaxin Li / Qinyu Zhu / Hao Shen / Ning Gao / Junyu Xiao / ![]() 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 ...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. | ||||||
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Structure visualization
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Structure viewer | Molecule: ![]() ![]() |
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Downloads & links
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Download
PDBx/mmCIF format | ![]() | 265.6 KB | Display | ![]() |
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PDB format | ![]() | 215.9 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
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-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 30004MC ![]() 6lxwC M: map data used to model this data C: citing same article ( |
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Similar structure data |
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Links
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Assembly
Deposited unit | ![]()
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Components
#1: Antibody | Mass: 31445.693 Da / Num. of mol.: 4 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #2: Protein | | Mass: 19225.762 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #3: Protein | | Mass: 63306.336 Da / Num. of mol.: 1 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: Ternary complex of IgA-Fc with the J chain and pIgR/SC Type: COMPLEX / Entity ID: all / Source: RECOMBINANT |
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Source (natural) | Organism: ![]() |
Source (recombinant) | Organism: ![]() |
Buffer solution | pH: 7.4 |
Specimen | Conc.: 0.3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE / Humidity: 100 % / Chamber temperature: 277.15 K |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company | |||||||||||||||
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Microscopy | Model: FEI TITAN KRIOS | |||||||||||||||
Electron gun | Electron source: ![]() | |||||||||||||||
Electron lens | Mode: BRIGHT FIELD | |||||||||||||||
Image recording |
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Processing
Software | Name: PHENIX / Version: 1.15.2_3472: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
Symmetry | Point symmetry: C1 (asymmetric) | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.15 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 665589 / Symmetry type: POINT | ||||||||||||||||||||||||
Refine LS restraints |
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