The vapB-vapC Operon of Acidovorax citrulli Functions as a Bona-fide Toxin-Antitoxin Module
Abstract
Toxin-antitoxin systems are commonly found on plasmids and chromosomes of bacteria and archaea. These systems appear as biscystronic genes encoding a stable toxin and a labile antitoxin, which protects the cells from the toxin's activity. Under specific, mostly stressful conditions, the unstable antitoxin is degraded, the toxin becomes active and growth is arrested. Using genome analysis we identified a putative toxin-antitoxin encoding system in the genome of the plant pathogen Acidovorax citrulli. The system is homologous to vapB-vapC systems from other bacterial species. PCR and phylogenetic analyses suggested that this locus is unique to group II strains of A. citrulli. Using biochemical and molecular analyses we show 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 its cognate VapB antitoxin. We further show that transcription of the A. citrulli vapBC locus is induced by amino acid starvation, chloramphenicol and during plant infection. Due to the possible role of TA systems in both virulence and dormancy of human pathogenic bacteria, studies of these systems are gaining a lot of attention. Conversely, studies characterizing ...Continue Reading
References
A VapBC toxin-antitoxin module is a posttranscriptional regulator of metabolic flux in mycobacteria.
Citations
Datasets Mentioned
Methods Mentioned
Software Mentioned
Related Concepts
Related Feeds
Archaeogenetics
Recent advances in genomic sequencing has led to the discovery of new strains of Archaea and shed light on their evolutionary history. Discover the latest research on Archaeogenetics here.