purinoceptor and its related proteins, member of the class A family of seven-transmembrane G protein-coupled receptors
Members of this subfamily include lysophosphatidic acid receptor, P2 purinoceptor, protease-activated receptor, platelet-activating factor receptor, Epstein-Barr virus induced gene 2, proton-sensing G protein-coupled receptors, GPR35, and GPR55, among others. All GPCRs have a common structural architecture comprising of seven-transmembrane (TM) alpha-helices interconnected by three extracellular and three intracellular loops. A general feature of GPCR signaling is agonist-induced conformational changes in the receptors, leading to activation of the heterotrimeric G proteins, which consist of the guanine nucleotide-binding G-alpha subunit and the dimeric G-beta-gamma subunits. The activated G proteins then bind to and activate numerous downstream effector proteins, which generate second messengers that mediate a broad range of cellular and physiological processes.
Comment:based on the structures of some class A family members (including purinoceptor-like subfamily members) with bound ligands (peptides or chemicals), agonists, or antagonists
Comment:Small-molecule chemical ligands tend to bind deeper within the receptor core, compared to a peptide ligand neurotensin, which binds towards the extracellular surface of its receptor.
Structure:4PXZ: Human P2Y12 receptor binds 2MeSADP, a close analogue of endogenous agonist ADP; contacts at 4A - View structure with Cn3D
Jiyao W et al.(2023). "The conserved domain database in 2023.",