Hier finden Sie wissenschaftliche Publikationen aus den Fraunhofer-Instituten.

In Vitro characterization of the type i toxin-antitoxin system bsrE/SR5 from Bacillus subtilis

: Meißner, C.; Jahn, N.; Brantl, S.


The Journal of biological chemistry 291 (2016), No.2, pp.560-571
ISSN: 0021-9258
ISSN: 1083-351X
Journal Article
Fraunhofer IZI ()

BsrE/SR5 is a new type I toxin/antitoxin system located on the prophage-like region P6 of the Bacillus subtilis chromosome. The bsrE gene encoding a 30-amino acid hydrophobic toxin and the antitoxin gene sr5 overlap at their 3′ ends by 112 bp. Overexpression of bsrE causes cell lysis on agar plates. Here, we present a detailed in vitro analysis of bsrE/SR5. The secondary structures of SR5, bsrE mRNA, and the SR5/bsrE RNA complex were determined. Apparent binding rate constants (kapp) of wild-type and mutated SR5 species with wild-type bsrE mRNA were calculated, and SR5 regions required for efficient inhibition of bsrE mRNA narrowed down. In vivo studies confirmed the in vitro data but indicated that a so far unknown RNA binding protein might exist in B. subtilis that can promote antitoxin/toxin RNA interaction. Using time course experiments, the binding pathway of SR5 and bsrE RNA was elucidated. A comparison with the previously well characterized type I TA system from the B. subtilis chromosome, bsrG/SR4, reveals similarities but also significant differences.