Document Type
Article
Version Deposited
Published Version
Publication Date
9-4-2020
Publication Title
Nucleic Acids Research
DOI
10.1093/nar/gkaa551
Abstract
Type II toxin-antitoxins systems are widespread in prokaryotic genomes. Typically, they comprise two proteins, a toxin, and an antitoxin, encoded by adjacent genes and forming a complex in which the enzymatic activity of the toxin is inhibited. Under stress conditions, the antitoxin is degraded liberating the active toxin. Though thousands of various toxin-antitoxins pairs have been predicted bioinformatically, only a handful has been thoroughly characterized. Here, we describe the AtaT2 toxin from a toxin-antitoxin system from Escherichia coli O157:H7. We show that AtaT2 is the first GNAT (Gcn5-related N-acetyltransferase) toxin that specifically targets charged glycyl tRNA. In vivo, the AtaT2 activity induces ribosome stalling at all four glycyl codons but does not evoke a stringent response. In vitro, AtaT2 acetylates the aminoacyl moiety of isoaccepting glycyl tRNAs, thus precluding their participation in translation. Our study broadens the known target specificity of GNAT toxins beyond the earlier described isoleucine and formyl methionine tRNAs, and suggest that various GNAT toxins may have evolved to specifically target other if not all individual aminoacyl tRNAs.
Recommended Citation
Ovchinnikov SV, Bikmetov D, Livenskyi A, Serebryakova M, Wilcox B, Mangano K, Shiriaev DI, Osterman IA, Sergiev PV, Borukhov S, Vazquez-Laslop N, Mankin AS, Severinov K, Dubiley S. Mechanism of translation inhibition by type II GNAT toxin AtaT2. Nucleic Acids Research. 2020 Sep 4;48(15):8617-8625. Epub 2020 Jun 29. doi: 10.1093/nar/gkaa551. PMID: 32597957. PMCID: PMC7470980.
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Published Citation
https://academic.oup.com/nar/article/48/15/8617/5864706
Included in
Bacteriology Commons, Bioinformatics Commons, Cell Biology Commons, Genomics Commons, Laboratory and Basic Science Research Commons, Medicine and Health Sciences Commons
Comments
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