Total modification of the bacteriophage lambda tail tube major subunit protein with foreign peptides

The bacteriophage lambda has been shown previously to tolerate a high multiplicity of peptide additions to the C-terminus of the major tail tube subunit protein (gpV, the product of the V gene). However, it was not clear whether all gpV copies within a functional virion could tolerate such modification. Complementation tests with phage bearing either V gene amber mutations or a precisely deleted V gene were used to test the extent of possible tail tube peptide display. Expression of plasmid-encoded gpV fused C-terminally with certain foreign peptides allowed rescue of such V gene-defective phage to essentially wild-type levels. After extensive purification such phage were shown by sensitive Western blotting to contain only the modified form of gpV. Peptide-modified gpV could also form indefinite tail tube polymeric structures (polytubes).