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.