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Open data
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Basic information
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Title | Focused refinement map of C3aR in JR14A-C3aR-Gi-scFv16 complex | |||||||||
![]() | Receptor-focused map of C3AR1-Gi-scFv16 complex with JR14A | |||||||||
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![]() | GPCR / MEMBRANE PROTEIN | |||||||||
Biological species | ![]() | |||||||||
Method | single particle reconstruction / cryo EM / Resolution: 2.8 Å | |||||||||
![]() | Kim J / Ko S / Choi H-J | |||||||||
Funding support | ![]()
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![]() | ![]() Title: Structural insights into small-molecule agonist recognition and activation of complement receptor C3aR. Authors: Jinuk Kim / Saebom Ko / Chulwon Choi / Jungnam Bae / Hyeonsung Byeon / Chaok Seok / Hee-Jung Choi / ![]() Abstract: The complement system plays crucial roles in innate immunity and inflammatory responses. The anaphylatoxin C3a mediates pro-inflammatory and chemotactic functions through the G protein-coupled ...The complement system plays crucial roles in innate immunity and inflammatory responses. The anaphylatoxin C3a mediates pro-inflammatory and chemotactic functions through the G protein-coupled receptor C3aR. While the active structure of the C3a-C3aR-G complex has been determined, the inactive conformation and activation mechanism of C3aR remain elusive. Here we report the cryo-EM structure of ligand-free, G protein-free C3aR, providing insights into its inactive conformation. In addition, we determine the structures of C3aR in complex with the synthetic small-molecule agonist JR14a in two distinct conformational states: a G protein-free intermediate, and a fully active G-bound state. The structure of the active JR14a-bound C3aR reveals that JR14a engages in highly conserved interactions with C3aR, similar to the binding of the C-terminal pentapeptide of C3a, along with JR14a-specific interactions. Structural comparison of C3aR in the apo, intermediate, and fully active states provides novel insights into the conformational landscape and activation mechanism of C3aR and defines a molecular basis explaining its high basal activity. Our results may aid in the rational design of therapeutics targeting complement-related inflammatory disorders. | |||||||||
History |
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Structure visualization
Supplemental images |
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Downloads & links
-EMDB archive
Map data | ![]() | 230.1 MB | ![]() | |
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Header (meta data) | ![]() ![]() | 15 KB 15 KB | Display Display | ![]() |
FSC (resolution estimation) | ![]() | 13.2 KB | Display | ![]() |
Images | ![]() | 33.7 KB | ||
Filedesc metadata | ![]() | 5 KB | ||
Others | ![]() ![]() | 226.3 MB 226.3 MB | ||
Archive directory | ![]() ![]() | HTTPS FTP |
-Related structure data
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Links
EMDB pages | ![]() ![]() |
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Map
File | ![]() | ||||||||||||||||||||||||||||||||||||
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Annotation | Receptor-focused map of C3AR1-Gi-scFv16 complex with JR14A | ||||||||||||||||||||||||||||||||||||
Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
Voxel size | X=Y=Z: 0.81 Å | ||||||||||||||||||||||||||||||||||||
Density |
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Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
Details | EMDB XML:
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-Supplemental data
-Half map: Half A map of Receptor-focused map
File | emd_60784_half_map_1.map | ||||||||||||
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Annotation | Half A map of Receptor-focused map | ||||||||||||
Projections & Slices |
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Density Histograms |
-Half map: Half B map of Receptor-focused map
File | emd_60784_half_map_2.map | ||||||||||||
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Annotation | Half B map of Receptor-focused map | ||||||||||||
Projections & Slices |
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Density Histograms |
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Sample components
-Entire : C3AR1-Gi complex
Entire | Name: C3AR1-Gi complex |
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Components |
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-Supramolecule #1: C3AR1-Gi complex
Supramolecule | Name: C3AR1-Gi complex / type: complex / ID: 1 / Parent: 0 / Macromolecule list: all |
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Source (natural) | Organism: ![]() |
Molecular weight | Theoretical: 140 kDa/nm |
-Macromolecule #1: C3aR
Macromolecule | Name: C3aR / type: protein_or_peptide / ID: 1 / Enantiomer: LEVO |
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Source (natural) | Organism: ![]() |
Recombinant expression | Organism: ![]() ![]() |
Sequence | String: DYKDDDDASI D MASFSAET NSTDLLSQPW NEPPVILSMV ILSLTFLLGL PGNGLVLWVA GLKMQRTVNT IWFLHLTLAD LLCCLSLPFS LAHLALQGQW PYGRFLCKLI PSIIVLNMFA SVFLLTAISL DRCLVVFKPI WCQNHRNVGM ACSICGCIWV VAFVMCIPVF ...String: DYKDDDDASI D MASFSAET NSTDLLSQPW NEPPVILSMV ILSLTFLLGL PGNGLVLWVA GLKMQRTVNT IWFLHLTLAD LLCCLSLPFS LAHLALQGQW PYGRFLCKLI PSIIVLNMFA SVFLLTAISL DRCLVVFKPI WCQNHRNVGM ACSICGCIWV VAFVMCIPVF VYREIFTTDN HNRCGYKFGL SSSLDYPDFY GDPLENRSLE NIVQPPGEMN DRLDPSSFQT NDHPWTVPTV FQPQTFQRPS ADSLPRGSAR LTSQNLYSNV FKPADVVSPK IPSGFPIEDH ETSPLDNSDA FLSTHLKLFP SASSNSFYES ELPQGFQDYY NLGQFTDDDQ VPTPLVAITI TRLVVGFLLP SVIMIACYSF IVFRMQRGRF AKSQSKTFRV AVVVVAVFLV CWTPYHIFGV LSLLTDPETP LGKTLMSWDH VCIALASANS CFNPFLYALL GKDFRKKARQ SIQGILEAAF SEELTRSTHC PSNNVISERN STTV ASLEV LFQ |
-Experimental details
-Structure determination
Method | cryo EM |
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![]() | single particle reconstruction |
Aggregation state | particle |
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Sample preparation
Buffer | pH: 8 |
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Vitrification | Cryogen name: ETHANE |
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Electron microscopy
Microscope | TFS KRIOS |
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Image recording | Film or detector model: FEI FALCON IV (4k x 4k) / Average electron dose: 60.0 e/Å2 |
Electron beam | Acceleration voltage: 300 kV / Electron source: ![]() |
Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Nominal defocus max: 2.0 µm / Nominal defocus min: 0.9 µm |
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |