SymE (SOS-induced yjiW gene with similarity to MazE ) is an SOS-induced toxin. It inhibits cell growth, decreases protein synthesis and increases RNA degradation. It may play a role in the recycling of RNAs damaged under SOS response-inducing conditions. It is predicted to have an AbrB fold, similar to that of the antitoxin MazE. Its translation is repressed by the antisense RNA SymR, which acts as an antitoxin [1,2].

1: RNA antitoxins. Gerdes K, Wagner EG; Curr Opin Microbiol. 2007;10:117-124. PMID:17376733

2: An antisense RNA controls synthesis of an SOS-induced toxin evolved from an antitoxin. Kawano M, Aravind L, Storz G; Mol Microbiol. 2007;64:738-754. PMID:17462020