Figure 16.
Top panels are ribbon diagrams of the PBPs. The bottom panels are close-ups of the substrate binding sites. Siderophores are shown in white stick and active site Tyr and Arg residues are indicated. A. Mtb FecB2 (PDB: 4PM4; blue), B. S. aureus heme:IsdE complex (PDB:2Q8Q; pink), and C. P. aeruginosa heme:PhuT complex (PDB:2R79; orange).