FIG. 7.

Model for lysis inhibition by S107. S105 and S107 molecules are represented by gray and black rectangles, respectively. The model assumes that holin dimers are the functional unit for the assembly of the membrane lesion; that S107 preferentially forms heterodimers with S105, which is in a twofold excess over S107; and that S105-S107 heterodimers are nonfunctional for hole formation. Once the first membrane lesion is formed the membrane potential (ΔΦ) collapses, which allows the inactive S105-S107 heterodimers to participate in hole formation.