PrlF_antitoxin is a family of bacterial antitoxins that neutralises the toxin YhaV. PrlF is labile and forms a homodimer that then binds to the YhaV toxin thereby neutralising its ribonuclease activity. Alone, it can also act as a transcription factor. The YhaV/PrlF complex binds the prlF-yhaV operon, probably regulating its expression negatively. Over-expression of PrlF leads to increased doubling time [1].

1: Increased expression of the bifunctional protein PrlF suppresses overproduction lethality associated with exported beta-galactosidase hybrid proteins in Escherichia coli. Kiino DR, Phillips GJ, Silhavy TJ; J Bacteriol 1990;172:185-192. PMID:2152898

2: prlF and yhaV encode a new toxin-antitoxin system in Escherichia coli. Schmidt O, Schuenemann VJ, Hand NJ, Silhavy TJ, Martin J, Lupas AN, Djuranovic S; J Mol Biol. 2007;372:894-905. PMID:17706670