Class B G protein-coupled receptors, an important class of therapeutic targets, signal mainly through the Gs class of heterotrimeric G proteins, although they do display some promiscuity in G protein binding. Using cryo-electron microscopy, we determined the structures of the human glucagon receptor (GCGR) bound to glucagon and distinct classes of heterotrimeric G proteins, Gs or Gi1 These two structures adopt a similar open binding cavity to accommodate Gs and Gi1 The Gs binding selectivity of GCGR is explained by a larger interaction interface, but there are specific interactions that affect Gi more than Gs binding. Conformational differences in the receptor intracellular loops were found to be key selectivity determinants. These distinctions in transducer engagement were supported by mutagenesis and functional studies.
International Workshop of 3D Molecular Imaging by Cryo-Electron Microscopy, Third K. H. Kuo Summer School of Electron Microscopy and Crystallography in 2010.
International Workshop of Advanced Image Processing of Cryo-Electron Microscopy, 2013
Get acquainted with Cryo-Electron Microscopy: First Chinese Workshop for Structural Biologists, 2015
International Workshop of Advanced Image Processing of Cryo-Electron Microscopy, 2015
Instutions
Instutions
Institute of Biophysics, Chinese Academy of Sciences
The Scripps Research Institute
Max Planck Institute of Biochemistry
Database
Database
National Center for Biotechnology Information(NCBI)
Protein Data Bank
The Electron Microscopy Data Bank
ExPASy Proteomics Server
Pfam
3D EM
3DEM
Tools and Softwars
Tools and Softwars
CCP4
CCP-EM
MOLE 2.0 (characterization of channels and pores in protein complex)
