Figure 3.

Binding of naturally occurring, semi-synthetic and next-generation aminoglycosides to AAC(2′)-Ia. Depicted in panels (a), (b), (c), and (d) are the Fo − Fc discovery maps for ligands tobramycin, netilmicin, amikacin, and plazomicin, respectively, at a contour level of 3σ. The plazomicin structure is presented here for comparison¹⁸. The enzyme is colored purple and the aminoglycosides tobramycin, netilmicin, amikacin, and plazomicin are colored in orange, red, teal, and violet, respectively.