Reut's toxin-antitoxin paper published

A manuscript entitled "The vapB-vapC operon of Acidovorax citrulli functions as a bona-fide toxin-antitoxin module" by Reut Shavit, Mario Lebendiker, Zohar Pasternak, Saul Burdman and Yael Helman, was published in 'Frontiers in Microbiology'. This article is part of the Ph.D. research of Reut Shavit. Toxin–antitoxin (TA) systems are commonly found in bacteria and archaea. These systems appear as biscystronic genes encoding a stable toxin and a labile antitoxin. Under certain conditions like stress, the unstable antitoxin is degraded, the toxin becomes active and growth is arrested. Using genome analysis we identified a putative TA system in the genome of A. citrulli. The system is homologous to vapB-vapC systems from other bacterial species. Interestingly, PCR and phylogenetic analyses suggest this locus is unique to group II strains of A. citrulli. Using biochemical and molecular analyses we showed that A. citrulli VapBC module is a bona-fide toxin–antitoxin module in which VapC is a toxin with ribonuclease activity that can be counteracted by the VapB antitoxin. We also showed that the transcription of the vapBC locus is induced by amino acid starvation, chloramphenicol and during plant tissue colonization.