A G protein-coupled receptor is comprised of ____ transmembrane α-helix/helices:

G protein-coupled receptors (GPCRs) are transmembrane proteins with ligand binding sites on the extracellular side of the membrane (near its N-terminal). What is the role of the G-protein in the GPCR signaling pathway?

G_i is the inhibitory G protein of various effector enzymes. If a toxin released from a bacterial infection enters cells & covalently modifies the α-subunit of G_i so that it can no longer bind GTP, which of the following is a likely result?