“…Repressors of other phages, for example, that of coliphage 186, are, by contrast, inactivated via protein-protein interactions with small antirepressor proteins (Shearwin et al, 1998). In these cases, production of the antirepressor is frequently controlled by a LexA-regulated promoter, and thus, despite different mechanisms, as in phage lambda, repressor inactivation is induced by the host SOS response (Heinzel et al, 1992;Kim et al, 2016;Lemire et al, 2011;Mardanov and Ravin, 2007;Quinones et al, 2005;Shearwin et al, 1998). Unlike autoproteolytic repressors, however, the mechanisms underlying antirepressor-mediated inactivation of phage repressors have seldom been fully characterized and it is possible that a given antirepressor can function by more than one mechanism.…”