Death by translation: ribosome‐assisted degradation of mRNA by endonuclease toxins

Belasco, Joel G.

doi:10.1002/1873-3468.12715

Cited by 1 publication

(1 citation statement)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under unfavorable conditions, especially under conditions of stress, antitoxins are depleted, allowing toxins to become free and to exert their toxic effect [1,2]. In this context, toxins from different TA systems may have variable cell targets, including DNA replication machinery [3][4][5], mRNA [6,7], cytoskeleton proteins [8], and membranes [9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Characterization of an OrtT-like toxin of Salmonella enterica serovar Houten

et al. 2019

View full text Add to dashboard Cite

The Escherichia coli GhoT/GhoS system is a type V toxin-antitoxin system in which the antitoxin GhoS cleaves the GhoT mRNA, controlling its translation. GhoT is a small hydrophobic protein that damages bacterial membranes. OrtT is a GhoT-like toxin, but it apparently lacks a corresponding antitoxin and serves a different physiologic role. Using a profile hidden Markov model approach, a Salmonella enterica serovar Houten genome was screened to obtain homologs of GhoT/OrtT. We only found one protein (referred to here as OrtT-Sal) that shared more sequence identity with OrtT than GhoT. The chromosomal region around the coding sequence of OrtT-Sal suggests that it is an orphan toxin and can be under RpoH activation. To study OrtT-Sal, we chemically synthesized and expressed in E. coli the whole toxin and its N-and C-terminal regions (OrtT-Sal 1-29 and OrtT-Sal 29-57 , respectively). Our findings have shown that the overproduction of the polypeptides resulted in severe growth inhibition and cell lysis. Using circular dichroism, we found that OrtT-Sal, OrtT-Sal 1-29 , and OrtT-Sal 29-57 form an alpha-helical structure in the presence of SDS micelles or TFE. Finally, using carboxyfluorescein-loaded lipid vesicles, we determined that the polypeptides damage lipid membrane directly.

show abstract