E protein causes host cell lysis by inhibiting MraY, a peptidoglycan biosynthesis enzyme. This leads to cell wall failure at septation [1]. The N terminal transmembrane region matches the signal peptide model and must be omitted from the family.

1: The Escherichia coli FKBP-type PPIase SlyD is required for the stabilization of the E lysis protein of bacteriophage phiX174. Bernhardt TG, Roof WD, Young R; Mol Microbiol 2002;45:99-108. PMID:12100551