Fig. 3. Structures of antibiotics targeting the interface and LSU.

The central ring shows a superimposition of the binding sites on the LSU (gray) of the antibiotics capreomycin (green), avilamycin (blue), lincomycin (red) and tiamulin (yellow), which is surrounded by insets highlighting the interactions between the drug and the rRNA (gray), waters (red spheres with gray transparent density), putative K⁺ ions (purple sphere with transparent gray density) and uL16 (orange). Potential hydrogen bonds are indicated as dashed lines, colored orange for direct interaction between the drug and the small subunit, cyan for water-mediated interactions, green for Mg²⁺ ion coordination and purple for K⁺ coordination.