Open AccessExpression of functional Bacillus SpoIISAB toxin–antitoxin modules in Escherichia coli
Author(s) -
Florek Patrik,
Muchová Katarína,
Pavelčíková Pamela,
Barák Imrich
Publication year - 2008
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2007.00984.x
Subject(s) - escherichia coli , antitoxin , biology , bacillus subtilis , microbiology and biotechnology , bacillus cereus , toxin , bacillus anthracis , transmembrane protein , gene , bacteria , biochemistry , genetics , receptor
SpoIISA and SpoIISB proteins from Bacillus subtilis belong to a recently described bacterial programmed‐cell death system. The current work demonstrates that the toxin–antitoxin module is also functional in Escherichia coli cells, where the expression of SpoIISA toxin leads to transient growth arrest coupled with cell lysis, and SpoIISA‐induced death can be prevented by coexpression of its cognate antitoxin, SpoIISB. Escherichia coli cells appear to be able to escape the SpoIISA killing by activation of a specific, as yet unidentified protease that cleaves out the cytosolic part of the protein. Analysis of the toxic effects of the transmembrane and cytosolic portions of SpoIISA showed that neither of them separately can function as a toxin; therefore, both parts of the protein have to act in concert to exert the killing. This work also identifies genes encoding putative homologues of SpoIISA and SpoIISB proteins on chromosomes of other Bacilli species. The SpoIISA‐like proteins from Bacillus anthracis and Bacillus cereus were shown to manifest the same effect on the viability of E. coli as their homologue from B. subtilis . Moreover, expression of the proposed spoIISB ‐like gene rescues E. coli cells from death induced by the SpoIISA homologue.