The C-Terminal Portion of the Tail Fiber Protein of Bacteriophage Lambda Is Responsible for Binding to LamB, Its Receptor at the Surface of Escherichia coli K-12

Bacteriophage λ adsorbs to its Escherichia coli K-12 host by interacting with LamB, its cell-surface receptor. We fused C-terminal portions of J, the tail fiber protein of λ, to maltose-binding protein. Solid-phase binding assays demonstrated that a purified fusion protein comprising only the last 249 residues of J could bind to LamB trimers and inhibited recognition by anti-LamB antibodies. Electron microscopy further demonstrated that the fusion protein could also bind to LamB at the surface of intact cells. This interaction prevented λ adsorption but affected only partially maltose uptake.