+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-34086 | |||||||||
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Title | Cryo-EM structure of four human FcmR bound to IgM-Fc/J | |||||||||
Map data | ||||||||||
Sample |
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Keywords | immunoglobin M / IMMUNE SYSTEM | |||||||||
Function / homology | Function and homology information high-affinity IgM receptor activity / immunoglobulin transcytosis in epithelial cells / IgM binding / hexameric IgM immunoglobulin complex / regulation of B cell receptor signaling pathway / polymeric immunoglobulin binding / IgM B cell receptor complex / dimeric IgA immunoglobulin complex / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex ...high-affinity IgM receptor activity / immunoglobulin transcytosis in epithelial cells / IgM binding / hexameric IgM immunoglobulin complex / regulation of B cell receptor signaling pathway / polymeric immunoglobulin binding / IgM B cell receptor complex / dimeric IgA immunoglobulin complex / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex / monomeric IgA immunoglobulin complex / secretory IgA immunoglobulin complex / Fc receptor-mediated immune complex endocytosis / IgA binding / pre-B cell allelic exclusion / IgM immunoglobulin complex / glomerular filtration / humoral immune response mediated by circulating immunoglobulin / CD22 mediated BCR regulation / immunoglobulin complex, circulating / immunoglobulin receptor binding / positive regulation of respiratory burst / humoral immune response / cellular defense response / Scavenging of heme from plasma / complement activation, classical pathway / antigen binding / trans-Golgi network membrane / Antigen activates B Cell Receptor (BCR) leading to generation of second messengers / Cell surface interactions at the vascular wall / B cell receptor signaling pathway / antibacterial humoral response / protein-macromolecule adaptor activity / early endosome membrane / protein-containing complex assembly / defense response to Gram-negative bacterium / blood microparticle / adaptive immune response / Potential therapeutics for SARS / immune response / lysosomal membrane / innate immune response / negative regulation of apoptotic process / cell surface / protein homodimerization activity / extracellular space / extracellular exosome / extracellular region / plasma membrane Similarity search - Function | |||||||||
Biological species | Homo sapiens (human) | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 3.71 Å | |||||||||
Authors | Li Y / Shen H / Xiao J | |||||||||
Funding support | China, 1 items
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Citation | Journal: Nature / Year: 2023 Title: Immunoglobulin M perception by FcμR. Authors: Yaxin Li / Hao Shen / Ruixue Zhang / Chenggong Ji / Yuxin Wang / Chen Su / Junyu Xiao / Abstract: Immunoglobulin M (IgM) is the first antibody to emerge during embryonic development and the humoral immune response. IgM can exist in several distinct forms, including monomeric, membrane-bound IgM ...Immunoglobulin M (IgM) is the first antibody to emerge during embryonic development and the humoral immune response. IgM can exist in several distinct forms, including monomeric, membrane-bound IgM within the B cell receptor (BCR) complex, pentameric and hexameric IgM in serum and secretory IgM on the mucosal surface. FcμR, the only IgM-specific receptor in mammals, recognizes different forms of IgM to regulate diverse immune responses. However, the underlying molecular mechanisms remain unknown. Here we delineate the structural basis of the FcμR-IgM interaction by crystallography and cryo-electron microscopy. We show that two FcμR molecules interact with a Fcμ-Cμ4 dimer, suggesting that FcμR can bind to membrane-bound IgM with a 2:1 stoichiometry. Further analyses reveal that FcμR-binding sites are accessible in the context of IgM BCR. By contrast, pentameric IgM can recruit four FcμR molecules to bind on the same side and thereby facilitate the formation of an FcμR oligomer. One of these FcμR molecules occupies the binding site of the secretory component. Nevertheless, four FcμR molecules bind to the other side of secretory component-containing secretory IgM, consistent with the function of FcμR in the retrotransport of secretory IgM. These results reveal intricate mechanisms of IgM perception by FcμR. | |||||||||
History |
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-Structure visualization
Supplemental images |
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-Downloads & links
-EMDB archive
Map data | emd_34086.map.gz | 114.6 MB | EMDB map data format | |
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Header (meta data) | emd-34086-v30.xml emd-34086.xml | 17.4 KB 17.4 KB | Display Display | EMDB header |
Images | emd_34086.png | 118.2 KB | ||
Filedesc metadata | emd-34086.cif.gz | 5.5 KB | ||
Others | emd_34086_half_map_1.map.gz emd_34086_half_map_2.map.gz | 116 MB 116 MB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-34086 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-34086 | HTTPS FTP |
-Validation report
Summary document | emd_34086_validation.pdf.gz | 1 MB | Display | EMDB validaton report |
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Full document | emd_34086_full_validation.pdf.gz | 1 MB | Display | |
Data in XML | emd_34086_validation.xml.gz | 14 KB | Display | |
Data in CIF | emd_34086_validation.cif.gz | 16.5 KB | Display | |
Arichive directory | https://ftp.pdbj.org/pub/emdb/validation_reports/EMD-34086 ftp://ftp.pdbj.org/pub/emdb/validation_reports/EMD-34086 | HTTPS FTP |
-Related structure data
Related structure data | 7ytdMC 7ysgC 7ytcC 7yteC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data | Similarity search - Function & homologyF&H Search |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_34086.map.gz / Format: CCP4 / Size: 125 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.828 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: #2
File | emd_34086_half_map_1.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Half map: #1
File | emd_34086_half_map_2.map | ||||||||||||
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Projections & Slices |
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Density Histograms |
-Sample components
-Entire : Cryo-EM structure of four human FcmR bound to IgM-Fc/J
Entire | Name: Cryo-EM structure of four human FcmR bound to IgM-Fc/J |
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Components |
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-Supramolecule #1: Cryo-EM structure of four human FcmR bound to IgM-Fc/J
Supramolecule | Name: Cryo-EM structure of four human FcmR bound to IgM-Fc/J type: complex / ID: 1 / Parent: 0 / Macromolecule list: #1-#3 |
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Source (natural) | Organism: Homo sapiens (human) |
-Supramolecule #2: Immunoglobulin heavy constant mu
Supramolecule | Name: Immunoglobulin heavy constant mu / type: complex / ID: 2 / Parent: 1 / Macromolecule list: #1 |
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Source (natural) | Organism: Homo sapiens (human) |
-Supramolecule #3: Immunoglobulin J chain
Supramolecule | Name: Immunoglobulin J chain / type: complex / ID: 3 / Parent: 1 / Macromolecule list: #2 |
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Source (natural) | Organism: Homo sapiens (human) |
-Supramolecule #4: FcmR
Supramolecule | Name: FcmR / type: complex / ID: 4 / Parent: 1 / Macromolecule list: #3 |
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-Macromolecule #1: Immunoglobulin heavy constant mu
Macromolecule | Name: Immunoglobulin heavy constant mu / type: protein_or_peptide / ID: 1 / Number of copies: 10 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 25.448598 KDa |
Recombinant expression | Organism: Homo sapiens (human) |
Sequence | String: IRVFAIPPSF ASIFLTKSTK LTCLVTDLTT YDSVTISWTR QNGEAVKTHT NISESHPNAT FSAVGEASIC EDDWNSGERF TCTVTHTDL PSPLKQTISR PKGVALHRPD VYLLPPAREQ LNLRESATIT CLVTGFSPAD VFVQWMQRGQ PLSPEKYVTS A PMPEPQAP ...String: IRVFAIPPSF ASIFLTKSTK LTCLVTDLTT YDSVTISWTR QNGEAVKTHT NISESHPNAT FSAVGEASIC EDDWNSGERF TCTVTHTDL PSPLKQTISR PKGVALHRPD VYLLPPAREQ LNLRESATIT CLVTGFSPAD VFVQWMQRGQ PLSPEKYVTS A PMPEPQAP GRYFAHSILT VSEEEWNTGE TYTCVVAHEA LPNRVTERTV DKSTGKPTLY NVSLVMSDTA GTC UniProtKB: Immunoglobulin heavy constant mu |
-Macromolecule #2: Immunoglobulin J chain
Macromolecule | Name: Immunoglobulin J chain / type: protein_or_peptide / ID: 2 / Number of copies: 1 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 15.483329 KDa |
Recombinant expression | Organism: Homo sapiens (human) |
Sequence | String: EDERIVLVDN KCKCARITSR IIRSSEDPNE DIVERNIRII VPLNNRENIS DPTSPLRTRF VYHLSDLCKK CDPTEVELDN QIVTATQSN ICDEDSATET CYTYDRNKCY TAVVPLVYGG ETKMVETALT PDACYPD UniProtKB: Immunoglobulin J chain |
-Macromolecule #3: Fas apoptotic inhibitory molecule 3
Macromolecule | Name: Fas apoptotic inhibitory molecule 3 / type: protein_or_peptide / ID: 3 / Number of copies: 4 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 11.723567 KDa |
Recombinant expression | Organism: Trichoplusia ni (cabbage looper) |
Sequence | String: RILPEVKVEG ELGGSVTIKC PLPEMHVRIY LCREMAGSGT CGTVVSTTNF IKAEYKGRVT LKQYPRKNLF LVEVTQLTES DSGVYACGA GMNTDRGKTQ KVTLNVHS UniProtKB: Immunoglobulin mu Fc receptor |
-Macromolecule #4: 2-acetamido-2-deoxy-beta-D-glucopyranose
Macromolecule | Name: 2-acetamido-2-deoxy-beta-D-glucopyranose / type: ligand / ID: 4 / Number of copies: 10 / Formula: NAG |
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Molecular weight | Theoretical: 221.208 Da |
Chemical component information | ChemComp-NAG: |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Buffer | pH: 7.4 |
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Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Average electron dose: 60.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 1.5 µm / Nominal defocus min: 1.0 µm |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
Startup model | Type of model: PDB ENTRY PDB model - PDB ID: |
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Final reconstruction | Resolution.type: BY AUTHOR / Resolution: 3.71 Å / Resolution method: FSC 0.143 CUT-OFF / Number images used: 202159 |
Initial angle assignment | Type: ANGULAR RECONSTITUTION |
Final angle assignment | Type: ANGULAR RECONSTITUTION |