fig6

Figure 6. Plasticity of P-gp’s drug-binding surface (A) The binding environment of the cyclic inhibitor QZ-Val in the mP-gp structure with D_COM of 45 Å (PDB:4M2T). The structure is rendered as a semi-transparent electrostatic surface with bound QZ-Val shown as stick models. The membrane bilayer is indicated by the two parallel horizontal lines. The inset is a magnified inhibitor binding environment viewed from the cytosolic side of P-gp toward the extracellular side. The bound whole QZ-Val is labeled as QZ-Val-1 and the half molecule is labeled as QZ-Val-2. (B) A different binding environment of the cyclic inhibitor QZ-Val in the mP-gp structure with D_COM of 60 Å (PDB:4Q9J). There are three modeled QZ-Val molecules labeled as QZ-Val-1’, QZ-Val-2’ and QZ-Val-3’