Figure 2

The spatial density \(\rho_{CMb} \left( {{\varvec{r}}_{cube} } \right)\) of the bosentan centroid around hETB. The iso-density map is presented at three contour levels with different colors, as shown in the inset. The molecular structure is the native complex (Figure S4) omitting solvent. Bosentan is shown as a cyan-colored stick model, with its centroid shown as a small black sphere. N-terminal tail and \(\beta\)-hairpin of hETB are indicated with labels. Red-colored contours are named “highest-density spots”. Blue-colored ones (\(\rho_{CMb} \left( {{\varvec{r}}_{cube} } \right) \ge 0.1\)) well specify the binding pocket of hETB. Magenta-colored regions above the pocket are designated as “hat”. Cyan-colored broken-lines represent the boundary, the hat–pocket boundary, which is called “gate” of the binding pocket. Figure S11, presents \(\rho_{CMb} \left( {{\varvec{r}}_{cube} } \right)\) with addition of two low-density contours of \(\rho_{CMb} \left( {{\varvec{r}}_{cube} } \right) \ge 0.001\) and \(0.0001\). Transmembrane helices (TM1–7) are labeled.