Figure 8 | Scientific Reports

Figure 8

From: The Bitter Taste Receptor TAS2R16 Achieves High Specificity and Accommodates Diverse Glycoside Ligands by using a Two-faced Binding Pocket

Figure 8

Summary of TAS2R16 residues critical for ligand binding and signaling. (a) TAS2R16 receptors with mutations at residues highlighted in blue signaled for at least one ligand, but failed to signal for another ligand. Residues highlighted in red failed to signal for all four ligands, but are expressed at wild-type levels on the cell surface. Signaling-critical residues that are highly conserved (>80% conservation among the 25 human TAS2R receptors) are circled in black. The N96 position which contributes to TAS2R16 probenecid sensitivity is shown in green. The residues implicated in ligand interactions (blue) are also shown on a TAS2R16 model structure (www.gpcrdb.org). The side view (b) suggests that the residues are located primarily in the membrane close to the extracellular side of the membrane, consistent with the locations identified in (a). TMs are identified by Roman numerals. The top-down view (c) suggests that the residues form a broad, two-sided ligand binding pocket.