Figure 4. The C-terminus of HK97 protease is sufficient for packaging proteins into HK97 proheads.

Proheads were made and purified using plasmids that express the HK97 major capsid protein gp5 and either wild-type protease, or gpD-protease fusion proteins made using several of the protease linker insertion mutants described in the text. The relative size and gp4 content of each is indicated in the figure. The lane on the right shows the protein composition of proheads made with the inactive protease mutant H65A for comparison. The predicted molecular weights for all protease variants are indicated at the bottom.