FIGURE 6.

Imipenem translocation through OmpC20 (a, front view; b, top view) and OmpC33 (c). The representative conformers of the different FES regions, labeled in Fig. 4, a and c, are reported in different colors: red, orange, blue, and purple for the minimum 1, 2, 3, and 4, respectively. Yellow is used for the representative conformer of the main energy barrier. The position of the positively charged nitrogen of the antibiotic is highlighted by a sphere, to provide a reference for its orientation inside the channel. Protein backbone is gray but the loop L3, which has been colored green.