7XP4

Cryo-EM structure of a class T GPCR in apo state

Summary for 7XP4

• Entry DOI: 10.2210/pdb7xp4/pdb
• EMDB information: 33364
• Descriptor: Guanine nucleotide-binding protein G(t) subunit alpha-3, Guanine nucleotide-binding protein G(I)/G(S)/G(T) subunit beta-1, Guanine nucleotide-binding protein G(I)/G(S)/G(O) subunit gamma-2, ... (5 entities in total)
• Functional Keywords: g protein-coupled receptor, taste type 2 receptors, cryo-electron microscopy structure, membrane protein
• Biological source: Homo sapiens; More
• Total number of polymer chains: 5
• Total formula weight: 184561.11

Authors

Liu, Z.J.,Hua, T.,Xu, W.X.,Wu, L.J. (deposition date: 2022-05-03, release date: 2022-10-12, Last modification date: 2024-11-20)

Primary citation

Xu, W.,Wu, L.,Liu, S.,Liu, X.,Cao, X.,Zhou, C.,Zhang, J.,Fu, Y.,Guo, Y.,Wu, Y.,Tan, Q.,Wang, L.,Liu, J.,Jiang, L.,Fan, Z.,Pei, Y.,Yu, J.,Cheng, J.,Zhao, S.,Hao, X.,Liu, Z.J.,Hua, T.
Structural basis for strychnine activation of human bitter taste receptor TAS2R46.
Science, 377:1298-1304, 2022

PubMed Abstract: Taste sensing is a sophisticated chemosensory process, and bitter taste perception is mediated by type 2 taste receptors (TAS2Rs), or class T G protein-coupled receptors. Understanding the detailed molecular mechanisms behind taste sensation is hindered by a lack of experimental receptor structures. Here, we report the cryo-electron microscopy structures of human TAS2R46 complexed with chimeric mini-G protein gustducin, in both strychnine-bound and apo forms. Several features of TAS2R46 are disclosed, including distinct receptor structures that compare with known GPCRs, a new "toggle switch," activation-related motifs, and precoupling with mini-G protein gustducin. Furthermore, the dynamic extracellular and more-static intracellular parts of TAS2R46 suggest possible diverse ligand-recognition and activation processes. This study provides a basis for further exploration of other bitter taste receptors and their therapeutic applications.

PubMed: 36108005
DOI: 10.1126/science.abo1633

Experimental method

ELECTRON MICROSCOPY (3.01 Å)