BrnT is a ribonuclease toxin of a type II toxin-antitoxin system that exhibits a RelE-like fold. The antitoxin that neutralises this toxin is Pfam:PF14384. BrnT is found in bacteria, archaea, bacteriophage, and plasmids. BrnT-BrnA forms a 2:2 tetrameric complex and autoregulates its own expression, which is induced by a number of different environmental stresses. Expression of BrnT alone results in cessation of bacterial growth which can be rescued after subsequent expression of BrnA [1].

1: Molecular structure and function of the novel BrnT/BrnA toxin-antitoxin system of Brucella abortus. Heaton BE, Herrou J, Blackwell AE, Wysocki VH, Crosson S; J Biol Chem. 2012;287:12098-12110. PMID:22334680