Molecular structure and function of the novel BrnT/BrnA toxin-antitoxin system of Brucella abortus.

ABSTRACT: Type II toxin-antitoxin (TA) systems are expressed from two-gene operons that encode a cytoplasmic protein toxin and its cognate protein antitoxin. These gene cassettes are often present in multiple copies on bacterial chromosomes, where they have been reported to regulate stress adaptation and persistence during antimicrobial treatment. We have identified a novel type II TA cassette in the intracellular pathogen Brucella abortus that consists of the toxin gene, brnT, and its antitoxin, brnA. BrnT is coexpressed and forms a 2:2 tetrameric complex with BrnA, which neutralizes BrnT toxicity. The BrnT(2)-BrnA(2) tetramer binds its own promoter via BrnA, and autorepresses its expression; its transcription is strongly induced in B. abortus by various stressors encountered by the bacterial cell

SUBMITTER: Heaton BE 

PROVIDER: S-EPMC3320955 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature