DNA/protein translocase of phage Salmonella phage P22 consisting of gp7, gp20, gp16 and gp26 (Perez et al., 2009). A homologue of gp20 in the phage Sf6 of S. flexneri, gp12, forms a decameric constricted channel though the outer member of the bacterium (Zhao et al. 2016). The other two recognized constituents of the Sf6 phage injectisome are gp11 (like gp7 of phage P22) and gp13 (like gp16 of phage P22).