Antitoxin component of a type II toxin-antitoxin (TA) system. Labile antitoxin that binds to its cognate MazF endoribonuclease toxin and neutralizes its activity. Both MazE and MazE-MazF bind to the promoter region of the mazE-mazF operon to inhibit their transcription. Forms a heterohexamer composed of alternating toxin and antitoxin homodimers MazF(2)-MazE(2)-MazF(2) which inhibits the endoribonuclease activity of MazF. Belongs to the PemI family.