8HS2

Orphan GPR20 in complex with Fab046


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.08 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

The activation mechanism and antibody binding mode for orphan GPR20.

Lin, X.Jiang, S.Wu, Y.Wei, X.Han, G.W.Wu, L.Liu, J.Chen, B.Zhang, Z.Zhao, S.Cherezov, V.Xu, F.

(2023) Cell Discov 9: 23-23

  • DOI: https://doi.org/10.1038/s41421-023-00520-8
  • Primary Citation of Related Structures:  
    8HS2, 8HS3, 8HSC

  • PubMed Abstract: 

    GPR20 is a class-A orphan G protein-coupled receptor (GPCR) and a potential therapeutic target for gastrointestinal stromal tumors (GIST) owing to its differentially high expression. An antibody-drug conjugate (ADC) containing a GPR20-binding antibody (Ab046) was recently developed in clinical trials for GIST treatment. GPR20 constitutively activates Gi proteins in the absence of any known ligand, but it remains obscure how this high basal activity is achieved. Here we report three cryo-EM structures of human GPR20 complexes including Gi-coupled GPR20 in the absence or presence of the Fab fragment of Ab046 and Gi-free GPR20. Remarkably, the structures demonstrate a uniquely folded N-terminal helix capping onto the transmembrane domain and our mutagenesis study suggests a key role of this cap region in stimulating the basal activity of GPR20. We also uncover the molecular interactions between GPR20 and Ab046, which may enable the design of tool antibodies with enhanced affinity or new functionality for GPR20. Furthermore, we report the orthosteric pocket occupied by an unassigned density which might be essential for exploring opportunities for deorphanization.


  • Organizational Affiliation

    iHuman Institute, ShanghaiTech University, Pudong, Shanghai, China.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
heavy chain of Fab046A [auth B]247RattusMutation(s): 0 
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
Light chain of Fab046B [auth C]233RattusMutation(s): 0 
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
Soluble cytochrome b562,G-protein coupled receptor 20C [auth R]459Escherichia coliHomo sapiens
This entity is chimeric
Mutation(s): 2 
Gene Names: cybCGPR20
Membrane Entity: Yes 
UniProt & NIH Common Fund Data Resources
Find proteins for Q99678 (Homo sapiens)
Explore Q99678 
Go to UniProtKB:  Q99678
GTEx:  ENSG00000204882 
Find proteins for P0ABE7 (Escherichia coli)
Explore P0ABE7 
Go to UniProtKB:  P0ABE7
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UniProt GroupsQ99678P0ABE7
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.08 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Not funded--

Revision History  (Full details and data files)

  • Version 1.0: 2023-03-08
    Type: Initial release
  • Version 1.1: 2023-03-15
    Changes: Database references