+Open data
-Basic information
Entry | Database: EMDB / ID: EMD-22591 | |||||||||
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Title | Structure of Secretory IgM Core | |||||||||
Map data | Secretory IgM Core | |||||||||
Sample |
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Function / homology | Function and homology information hexameric IgM immunoglobulin complex / polymeric immunoglobulin receptor activity / immunoglobulin transcytosis in epithelial cells mediated by polymeric immunoglobulin receptor / dimeric IgA immunoglobulin complex / IgM B cell receptor complex / polymeric immunoglobulin binding / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex / monomeric IgA immunoglobulin complex / secretory IgA immunoglobulin complex ...hexameric IgM immunoglobulin complex / polymeric immunoglobulin receptor activity / immunoglobulin transcytosis in epithelial cells mediated by polymeric immunoglobulin receptor / dimeric IgA immunoglobulin complex / IgM B cell receptor complex / polymeric immunoglobulin binding / secretory dimeric IgA immunoglobulin complex / pentameric IgM immunoglobulin complex / monomeric IgA immunoglobulin complex / secretory IgA immunoglobulin complex / Fc receptor signaling pathway / IgA binding / detection of chemical stimulus involved in sensory perception of bitter taste / glomerular filtration / pre-B cell allelic exclusion / IgM immunoglobulin complex / CD22 mediated BCR regulation / azurophil granule membrane / receptor clustering / immunoglobulin complex, circulating / immunoglobulin receptor binding / positive regulation of respiratory burst / humoral immune response / Scavenging of heme from plasma / complement activation, classical pathway / antigen binding / Antigen activates B Cell Receptor (BCR) leading to generation of second messengers / Cell surface interactions at the vascular wall / B cell receptor signaling pathway / epidermal growth factor receptor signaling pathway / protein-macromolecule adaptor activity / antibacterial humoral response / protein-containing complex assembly / blood microparticle / defense response to Gram-negative bacterium / Potential therapeutics for SARS / adaptive immune response / receptor complex / immune response / innate immune response / Neutrophil degranulation / 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: 3.3 Å | |||||||||
Authors | Kumar N / Arthur CP / Ciferri C / Matsumoto ML | |||||||||
Citation | Journal: Structure / Year: 2021 Title: Structure of the human secretory immunoglobulin M core. Authors: Nikit Kumar / Christopher P Arthur / Claudio Ciferri / Marissa L Matsumoto / Abstract: Immunoglobulins (Ig) A and M are the only human antibodies that form oligomers and undergo transcytosis to mucosal secretions via the polymeric Ig receptor (pIgR). When complexed with the J-chain (JC) ...Immunoglobulins (Ig) A and M are the only human antibodies that form oligomers and undergo transcytosis to mucosal secretions via the polymeric Ig receptor (pIgR). When complexed with the J-chain (JC) and the secretory component (SC) of pIgR, secretory IgA and IgM (sIgA and sIgM) play critical roles in host-pathogen defense. Recently, we determined the structure of sIgA-Fc which elucidated the mechanism of polymeric IgA assembly and revealed an extensive binding interface between IgA-Fc, JC, and SC. Despite low sequence identity shared with IgA-Fc, IgM-Fc also undergoes JC-mediated assembly and binds pIgR. Here, we report the structure of sIgM-Fc and carryout a systematic comparison to sIgA-Fc. Our structural analysis reveals a remarkably conserved mechanism of JC-templated oligomerization and SC recognition of both IgM and IgA through a highly conserved network of interactions. These studies reveal the structurally conserved features of sIgM and sIgA required for function in mucosal immunity. | |||||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | EM map: SurfViewMolmilJmol/JSmol |
Supplemental images |
-Downloads & links
-EMDB archive
Map data | emd_22591.map.gz | 226.6 MB | EMDB map data format | |
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Header (meta data) | emd-22591-v30.xml emd-22591.xml | 14.6 KB 14.6 KB | Display Display | EMDB header |
Images | emd_22591.png | 106.1 KB | ||
Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-22591 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-22591 | HTTPS FTP |
-Related structure data
Related structure data | 7k0cMC M: atomic model generated by this map C: citing same article (ref.) |
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Similar structure data |
-Links
EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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Related items in Molecule of the Month |
-Map
File | Download / File: emd_22591.map.gz / Format: CCP4 / Size: 244.1 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Annotation | Secretory IgM Core | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 1.2 Å | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
CCP4 map header:
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-Supplemental data
-Sample components
-Entire : Structure of the Human Secretory Immunoglobulin M Core
Entire | Name: Structure of the Human Secretory Immunoglobulin M Core |
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Components |
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-Supramolecule #1: Structure of the Human Secretory Immunoglobulin M Core
Supramolecule | Name: Structure of the Human Secretory Immunoglobulin M Core type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
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Source (natural) | Organism: Homo sapiens (human) |
Recombinant expression | Organism: Cricetulus griseus (Chinese hamster) |
Molecular weight | Theoretical: 480 kDa/nm |
-Macromolecule #1: Polymeric immunoglobulin receptor
Macromolecule | Name: Polymeric immunoglobulin receptor / type: protein_or_peptide / ID: 1 / Number of copies: 1 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 65.154094 KDa |
Recombinant expression | Organism: Cricetulus griseus (Chinese hamster) |
Sequence | String: KSPIFGPEEV NSVEGNSVSI TCYYPPTSVN RHTRKYWCRQ GARGGCITLI SSEGYVSSKY AGRANLTNFP ENGTFVVNIA QLSQDDSGR YKCGLGINSR GLSFDVSLEV SQGPGLLNDT KVYTVDLGRT VTINCPFKTE NAQKRKSLYK QIGLYPVLVI D SSGYVNPN ...String: KSPIFGPEEV NSVEGNSVSI TCYYPPTSVN RHTRKYWCRQ GARGGCITLI SSEGYVSSKY AGRANLTNFP ENGTFVVNIA QLSQDDSGR YKCGLGINSR GLSFDVSLEV SQGPGLLNDT KVYTVDLGRT VTINCPFKTE NAQKRKSLYK QIGLYPVLVI D SSGYVNPN YTGRIRLDIQ GTGQLLFSVV INQLRLSDAG QYLCQAGDDS NSNKKNADLQ VLKPEPELVY EDLRGSVTFH CA LGPEVAN VAKFLCRQSS GENCDVVVNT LGKRAPAFEG RILLNPQDKD GSFSVVITGL RKEDAGRYLC GAHSDGQLQE GSP IQAWQL FVNEESTIPR SPTVVKGVAG GSVAVLCPYN RKESKSIKYW CLWEGAQNGR CPLLVDSEGW VKAQYEGRLS LLEE PGNGT FTVILNQLTS RDAGFYWCLT NGDTLWRTTV EIKIIEGEPN LKVPGNVTAV LGETLKVPCH FPCKFSSYEK YWCKW NNTG CQALPSQDEG PSKAFVNCDE NSRLVSLTLN LVTRADEGWY WCGVKQGHFY GETAAVYVAV EERKAAGSRD VSLAKA DAA PDEKVLDSGF REIENKAIQD PRHHHHHH |
-Macromolecule #2: Immunoglobulin heavy constant mu
Macromolecule | Name: Immunoglobulin heavy constant mu / type: protein_or_peptide / ID: 2 / Number of copies: 10 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 40.677605 KDa |
Recombinant expression | Organism: Cricetulus griseus (Chinese hamster) |
Sequence | String: DYKDDDDKLE VLFQGPGSLP VIAELPPKVS VFVPPRDGFF GNPRKSKLIC QATGFSPRQI QVSWLREGKQ VGSGVTTDQV QAEAKESGP TTYKVTSTLT IKESDWLGQS MFTCRVDHRG LTFQQNASSM CVPDQDTAIR VFAIPPSFAS IFLTKSTKLT C LVTDLTTY ...String: DYKDDDDKLE VLFQGPGSLP VIAELPPKVS VFVPPRDGFF GNPRKSKLIC QATGFSPRQI QVSWLREGKQ VGSGVTTDQV QAEAKESGP TTYKVTSTLT IKESDWLGQS MFTCRVDHRG LTFQQNASSM CVPDQDTAIR VFAIPPSFAS IFLTKSTKLT C LVTDLTTY DSVTISWTRQ NGEAVKTHTN ISESHPNATF SAVGEASICE DDWNSGERFT CTVTHTDLPS PLKQTISRPK GV ALHRPDV YLLPPAREQL NLRESATITC LVTGFSPADV FVQWMQRGQP LSPEKYVTSA PMPEPQAPGR YFAHSILTVS EEE WNTGET YTCVVAHEAL PNRVTERTVD KSTGKPTLYN VSLVMSDTAG TCY |
-Macromolecule #3: Immunoglobulin J chain
Macromolecule | Name: Immunoglobulin J chain / type: protein_or_peptide / ID: 3 / Number of copies: 1 / Enantiomer: LEVO |
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Source (natural) | Organism: Homo sapiens (human) |
Molecular weight | Theoretical: 15.611458 KDa |
Recombinant expression | Organism: Cricetulus griseus (Chinese hamster) |
Sequence | String: QEDERIVLVD NKCKCARITS RIIRSSEDPN EDIVERNIRI IVPLNNRENI SDPTSPLRTR FVYHLSDLCK KCDPTEVELD NQIVTATQS NICDEDSATE TCYTYDRNKC YTAVVPLVYG GETKMVETAL TPDACYPD |
-Experimental details
-Structure determination
Method | cryo EM |
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Processing | single particle reconstruction |
Aggregation state | particle |
-Sample preparation
Concentration | 0.2 mg/mL | |||||||||
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Buffer | pH: 7.2 Component:
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Grid | Model: UltrAuFoil R0.6/1 / Material: GOLD / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY / Support film - Film thickness: 2.5 nm / Pretreatment - Type: GLOW DISCHARGE | |||||||||
Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277 K / Instrument: FEI VITROBOT MARK IV Details: Blot for 3.5 seconds before plunging with blot force 7.. | |||||||||
Details | Sample was monodisperse. |
-Electron microscopy
Microscope | FEI TITAN KRIOS |
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Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELDBright-field microscopy / Cs: 2.7 mm / Nominal magnification: 165000 |
Sample stage | Specimen holder model: FEI TITAN KRIOS AUTOGRID HOLDER / Cooling holder cryogen: NITROGEN |
Image recording | Film or detector model: GATAN K2 SUMMIT (4k x 4k) / Detector mode: COUNTING / Average exposure time: 0.2 sec. / Average electron dose: 1.02 e/Å2 |
Experimental equipment | Model: Titan Krios / Image courtesy: FEI Company |
-Image processing
CTF correction | Software - Name: CTFFIND (ver. 4) |
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Initial angle assignment | Type: ANGULAR RECONSTITUTION / Software - Name: cisTEM |
Final angle assignment | Type: ANGULAR RECONSTITUTION |
Final reconstruction | Applied symmetry - Point group: C1 (asymmetric) / Resolution.type: BY AUTHOR / Resolution: 3.3 Å / Resolution method: FSC 0.143 CUT-OFF / Software - Name: cisTEM / Number images used: 244123 |