The transporter–opsin–G protein-coupled receptor (TOG) superfamily (pages 5780–5800)
Daniel C. Yee, Maksim A. Shlykov, Åke Västermark, Vamsee S. Reddy, Sumit Arora, Eric I. Sun and Milton H. Saier Jr
Article first published online: 23 SEP 2013 | DOI: 10.1111/febs.12499
The TOG superfamily is believed to have arisen from a 4-TMS precursor that duplicated to an 8-TMS precursor, common to the superfamily constituents, before diverging in topology via the loss or gain of specific TMSs. The 4-TMS duplication may have occurred more than once during the TOG superfamily evolution. This pathway does not exclude other possible routes.