Txe, an endoribonuclease of the enterococcal Axe–Txe toxin–antitoxin system, cleaves mRNA and inhibits protein synthesis
Open Access
- 1 February 2011
- journal article
- Published by Microbiology Society in Microbiology
- Vol. 157 (2), 387-397
- https://doi.org/10.1099/mic.0.045492-0
Abstract
The axe–txe operon encodes a toxin–antitoxin (TA) pair, Axe–Txe, that was initially identified on the multidrug-resistance plasmid pRUM in Enterococcus faecium. In Escherichia coli, expression of the Txe toxin is known to inhibit cell growth, and co-expression of the antitoxin, Axe, counteracts the toxic effect of Txe. Here, we report the nucleotide sequence of pS177, a 39 kb multidrug-resistant plasmid isolated from vancomycin-resistant Ent. faecium, which harbours the axe–txe operon and the vanA gene cluster. RT-PCR analysis revealed that the axe–txe transcript is produced by strain S177 as well as by other vancomycin-resistant enteroccoci. Moreover, we determine the mechanism by which the Txe protein exerts its toxic activity. Txe inhibits protein synthesis in E. coli without affecting DNA or RNA synthesis, and inhibits protein synthesis in a cell-free system. Using in vivo primer extension analysis, we demonstrate that Txe preferentially cleaves single-stranded mRNA at the first base after an AUG start codon. We conclude that Txe is an endoribonuclease which cleaves mRNA and inhibits protein synthesis.Keywords
This publication has 52 references indexed in Scilit:
- Antimicrobial susceptibility of Gram-positive bacteria isolated from US medical centers: results of the Daptomycin Surveillance Program (2007–2008)Diagnostic Microbiology and Infectious Disease, 2009
- Staphylococcus aureus YoeB Homologues Inhibit Translation InitiationJournal of Bacteriology, 2009
- Comprehensive comparative-genomic analysis of Type 2 toxin-antitoxin systems and related mobile stress response systems in prokaryotesBiology Direct, 2009
- The Inhibitory Mechanism of Protein Synthesis by YoeB, an Escherichia coli ToxinJournal of Biological Chemistry, 2009
- Structure and Proposed Activity of a Member of the VapBC Family of Toxin-Antitoxin SystemsJournal of Biological Chemistry, 2009
- Translation affects YoeB and MazF messenger RNA interferase activities by different mechanismsNucleic Acids Research, 2008
- Exposing plasmids as the Achilles’ heel of drug-resistant bacteriaCurrent Opinion in Chemical Biology, 2008
- Comparative DNA Analysis of Two vanA Plasmids from Enterococcus faecium Strains Isolated from Poultry and a Poultry Farmer in NorwayAntimicrobial Agents and Chemotherapy, 2007
- Toxin–antitoxin systems are ubiquitous and plasmid-encoded in vancomycin-resistant enterococciProceedings of the National Academy of Sciences, 2007
- Basic local alignment search toolJournal of Molecular Biology, 1990