4ERS

A Molecular Basis for Negative Regulation of the Glucagon Receptor


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.637 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.231 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Molecular basis for negative regulation of the glucagon receptor.

Koth, C.M.Murray, J.M.Mukund, S.Madjidi, A.Minn, A.Clarke, H.J.Wong, T.Chiang, V.Luis, E.Estevez, A.Rondon, J.Zhang, Y.Hotzel, I.Allan, B.B.

(2012) Proc.Natl.Acad.Sci.USA 109: 14393-14398

  • DOI: 10.1073/pnas.1206734109

  • PubMed Abstract: 
  • Members of the class B family of G protein-coupled receptors (GPCRs) bind peptide hormones and have causal roles in many diseases, ranging from diabetes and osteoporosis to anxiety. Although peptide, small-molecule, and antibody inhibitors of these G ...

    Members of the class B family of G protein-coupled receptors (GPCRs) bind peptide hormones and have causal roles in many diseases, ranging from diabetes and osteoporosis to anxiety. Although peptide, small-molecule, and antibody inhibitors of these GPCRs have been identified, structure-based descriptions of receptor antagonism are scarce. Here we report the mechanisms of glucagon receptor inhibition by blocking antibodies targeting the receptor's extracellular domain (ECD). These studies uncovered a role for the ECD as an intrinsic negative regulator of receptor activity. The crystal structure of the ECD in complex with the Fab fragment of one antibody, mAb1, reveals that this antibody inhibits glucagon receptor by occluding a surface extending across the entire hormone-binding cleft. A second antibody, mAb23, blocks glucagon binding and inhibits basal receptor activity, indicating that it is an inverse agonist and that the ECD can negatively regulate receptor activity independent of ligand binding. Biochemical analyses of receptor mutants in the context of a high-resolution ECD structure show that this previously unrecognized inhibitory activity of the ECD involves an interaction with the third extracellular loop of the receptor and suggest that glucagon-mediated structural changes in the ECD accompany receptor activation. These studies have implications for the design of drugs to treat class B GPCR-related diseases, including the potential for developing novel allosteric regulators that target the ECDs of these receptors.


    Organizational Affiliation

    Department of Structural Biology, Molecular Biology, Antibody Engineering, Protein Chemistry, and Early Discovery Biochemistry, Genentech Inc, South San Francisco, CA 94080, USA. koth.christopher@gene.com




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Fab light chain
L
214N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Fab heavy chain
H
231N/A
Protein Feature View is not available: No corresponding UniProt sequence found.
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
Glucagon receptor
A
96Homo sapiensGene Names: GCGR
Find proteins for P47871 (Homo sapiens)
Go to Gene View: GCGR
Go to UniProtKB:  P47871
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
NAG
Query on NAG

Download SDF File 
Download CCD File 
A
N-ACETYL-D-GLUCOSAMINE
C8 H15 N O6
OVRNDRQMDRJTHS-FMDGEEDCSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.637 Å
  • R-Value Free: 0.279 
  • R-Value Work: 0.231 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 46.410α = 90.00
b = 62.250β = 93.91
c = 104.940γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
XSCALEdata scaling
PDB_EXTRACTdata extraction
SCALAdata scaling
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2012-08-29
    Type: Initial release
  • Version 1.1: 2012-10-17
    Type: Database references
  • Version 1.2: 2012-12-05
    Type: Derived calculations