An online resource for GPCR structure determination and analysis

Abstract

G protein-coupled receptors (GPCRs) transduce physiological and sensory stimuli into appropriate cellular responses and mediate the actions of one-third of drugs. GPCR structural studies have revealed the general bases of receptor activation, signalling, drug action and allosteric modulation, but so far cover only 13% of non-olfactory receptors. We broadly surveyed the receptor modifications/engineering and methods used to produce all available GPCR crystal and cryo-EM structures and present an interactive resource integrated in GPCRdb (www.gpcrdb.org) to assist users in designing constructs and browsing appropriate experimental conditions for structure studies.

Cryo-EM structure of the rhodopsin-Gαi-βγ complex reveals binding of the rhodopsin C-terminal tail to the Gβ subunit

“…one of the most diverse regions in GPCRs, is often not completely resolved in the 231 available structures (Suppl.Fig. 7D), either because it is too flexible or because it has been 232 engineered to facilitate structural determination(Munk et al, 2019). Gi/o-coupled receptors 233 use residues on TM5/ICL3/TM6 to contact the α4/β6 region, while Gs-coupled receptors 234 mainly use TM5/ICL3 (Suppl.Fig.…”

Structure and Function of GPCRs

“…It is not until 2007 that a structure of another receptor, the b2adrenergic receptor, came out (Cherezov et al, 2007;Rasmussen et al, 2007). Since then, the number of crystal structures of GPCRs (and other membrane proteins) has been growing due to advances in crystallization and high-resolution X-ray and more recently also in cryogenic electron microscopy (cryo-EM) techniques ( Figure 1.1) (Munk et al, 2019). These advances in GPCRs crystallization include stabilization via chimeric proteins such as T4 lysozyme (T4L) or BRIL in place of intracellular loop 3 (ICL3) or at N-terminus, thermostabilization by point mutations, use of high affinity ligands and/or a nanobody, which is a single domain of the antigen-binding fragment (Fab fragment) of antibodies, which mimic G proteins (Chun et al, 2012;Manglik, Kobilka and Steyaert, 2017).…”

The mutational landscape of human olfactory G protein-coupled receptors

“…A detailed topological localization system was developed to assign each mutation to a region within the seven alpha helical bundle molecular architecture characteristic of GPCRs (i.e. extracellular and intracellular N-and C-terminal sequences, seven transmembrane α-helices [TM 1 to 7], three extracellular [ECL 1 to 3] and three cytoplasmic loops [ICL 1 to 3]) [20,21]. This system also includes the assignation of unambiguously positions to all mutations occurring in the TM helices according to the numbering systems developed by Ballesteros-Weinstein (BW) and others for this family of proteins [22,23].…”