Efficient phage display of polypeptides fused to the carboxy-terminus of the M13 gene-3 minor coat protein.

We report that, contrary to common belief, polypeptides fused to the carboxy-terminus of the M13 gene-3 minor coat protein are functionally displayed on the phage surface. In a phagemid display system, carboxy-terminal fusion through optimized linker sequences resulted in display levels comparable to those achieved with conventional amino-terminal fusions. These findings are of considerable importance to phage display technology because they enable investigations not suited to amino-terminal display, including the study of protein-protein interactions requiring free carboxy-termini, functional cDNA cloning efforts, and the display of intracellular proteins.