Figure 3.

Schematic of the domain structure of mTOR showing the N-terminus with two tandem HEAT repeats, followed by a FAT domain (domain shared by PI3K-related protein kinases (PIKK) family members), an FRB domain (FKBP-12-rapamycin-binding site), a kinase catalytic domain, a repressor domain (RD), and a FAT C terminus domain located at the C-terminus of the protein. The FRB domain forms a deep hydrophobic cleft that serves as the high-affinity binding site for the inhibitory complex FKBP12-rapamycin [52].