Figure 5

The tertiary structure of the PepT1, predicted at the I-TASSER server, is characterized by 12 transmembrane domains, shaped as alpha helices, and longer enough to completely pass the all thickness of the lipid bilayer (60 vs 45 Å). The protein starts and ends at the inner side of the bilayer. This feature is typical of channel proteins, to which the PepT1 belongs. A long chain not embedded in the bilayer is present. The transmembrane helices are here depicted in yellow or green, being the last one located inside the PTR2 domain.