Bacterial Bacteria ( Cook Et ) System Are Found Throughout The Prokaryotic Kingdom
929 WordsApr 10, 20154 Pages
Bacterial toxin-antitoxin [TA] system are found throughout the prokaryotic kingdom (Cook et al. 2013; Bertram & Schuster 2014). The TA system plays a very important role in stress conditions that prevail in environments unfavorable for growth, for ex. amino acid starvation, higher/lower temperatures, pH, oxidative stress, etc. (Yamaguchi et al. 2011; Van Melderen & Saavedra De Bast 2009). TA systems are not essential for general bacterial growth. However, the bacterium continuously produces them investing a lot of energy. They are bicistronic elements that encode i) A toxin: A protein that negatively interferes with vital cellular functions in bacteria and ii) An antitoxin : A protein or an RNA molecule that keeps this toxin in check (Goeders & Van Melderen 2013). Both toxin and antitoxin are produced together however, toxin is more stable than antitoxin. Antitoxin therefore, is produced continuously to keep the effect of toxin in check (Gerdes & Maisonneuve 2012; Park et al. 2013). The toxin is known to effect bacterial functioning at variety of actions like cleaving DNA (Kunin & Ouzounis 2003; Pandey & Gerdes 2005) and RNA (Muñoz-Gómez et al. 2004; Yamaguchi & Inouye 2009), inhibition of ATP synthesis (Unoson & Wagner 2008), phosphorylation of proteins(Schumacher et al. 2009), etc.
There are three types of TA system (Yamaguchi et al. 2011) represented in Fig 1 (Park et al. 2013). In type I TA system mRNA antitoxin is cotranscribed with an mRNA for toxin. Antitoxin mRNA