BsrE/SR5: a novel type I toxin-antitoxin system in Bacillus subtilis: Localization of the toxin and identification of its cellular target(s), mechanism(s) of antitoxin action, and biological functions of the system

• Applicant: Privatdozentin Dr. Sabine Brantl
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2015 to 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 276973612

Toxin/antitoxin systems (TA systems) are pairs of adjacent genes, one of which encodes a stable toxic peptide that is neutralized by an unstable antitoxin coded by the neighbouring gene. Currently, 5 types of TA systems are known. In type I TA systems, the antitoxin is a small regulatory RNA, which interacts with the toxin mRNA, and interaction results in inhibition of toxin translation or/and degradation of the toxin mRNA. Whereas the function of plasmid-encoded TA systems has been investigated and elucidated a long time ago (they are post-segregational killing systems, i.e. they cause the death of plasmid free cells), the biological function and importance of chromosomal type I TA systems is still a matter of speculation. In this project, we plan to investigate a new chromosome-encoded type I TA system from Bacillus subtilis, bsrE/SR5, with regard to three aspects: 1) Cellular localization of the toxic peptide, its cellular target(s) and its/their biochemical activities. As a novelty, we will use cutting-edge techniques from cell biology to identify toxin targets. 2) Mechanism of action of the RNA antitoxin 3) Biological function/importance of this system for Bacillus subtilis.

• DFG Programme: Research Grants