An [{Fe(mecam)}2]6− Bridge in the Crystal Structure of a Ferric Enterobactin Binding Protein

Bridging the gap: The dinuclear ferric enterobactin mimic [{Fe(mecam)}2]6− (H6-mecam=1,3,5-N,N′,N′′-tris(2,3-dihydroxybenzoyl)triaminomethylbenzene) is recognized by two periplasmic binding protein molecules (yellow and blue; see structure). The assembly is stabilized through hydrophobic interactions between the ligand backbones of the dinuclear iron complex.