TOG superfamily
The transporter-opsin-G protein-coupled receptor (TOG) superfamily is a protein superfamily of integral membrane proteins, usually of 7 or 8 transmembrane alpha-helical segments (TMSs). It includes (1) ion-translocating microbial rhodopsins, (2) G protein-coupled receptors (GPCRs), (3) sweet sugar transporters, (4) nicotinamide ribonucleoside uptake permeases (PnuCs; TC# 4.B.1), (5) 4-toluene sulfonate uptake permeases (TSUPs; TC# 2.A.102), (6) Ni2+–Co2+ transporters; (NiCoTs; TC# 2.A.52), (7) organic solute transporters (OSTs; TC# 2.A.82), (8) phosphate:Na+ symporters (PNaS; TC# 2.A.58), and (9) lysosomal cystine transporters (LCTs; TC# 2.A.43).