Identification of an Outer Membrane Protein Responsible for the Binding of the Fe-Enterochelin Complex to Escherichia coli Cells1

Escherichia coli incorporates iron as a complex with enterochelin. By using mutants which lack one or the other, or both, of the outer membrane proteins, O-2b and O-3, we have shown that protein O-2b (feuB protein) is responsible for the primary binding of the iron-enterochelin complex to the outer membrane in the process of iron transport.