A Stress-Induced Bias in the Reading of the Genetic Code in Escherichia coli
Abstract
Escherichia coli mazEF is an extensively studied stress-induced toxin-antitoxin (TA) system. The toxin MazF is an endoribonuclease that cleaves RNAs at ACA sites. Thereby, under stress, the induced MazF generates a stress-induced translation machinery (STM), composed of MazF-processed mRNAs and selective ribosomes that specifically translate the processed mRNAs. Here, we further characterized the STM system, finding that MazF cleaves only ACA sites located in the open reading frames of processed mRNAs, while out-of-frame ACAs are resistant. This in-frame ACA cleavage of MazF seems to depend on MazF binding to an extracellular-death-factor (EDF)-like element in ribosomal protein bS1 (bacterial S1), apparently causing MazF to be part of STM ribosomes. Furthermore, due to the in-frame MazF cleavage of ACAs under stress, a bias occurs in the reading of the genetic code causing the amino acid threonine to be encoded only by its synonym codon ACC, ACU, or ACG, instead of by ACA.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Dec 30, 2016
- Source ID
- 10.1128/mbio.01855-16
Entities
People
- Adi Oron-gottesman
- Hanna Engelberg-kulka
- Isabella Moll
- Martina Sauert
Organizations
- Austrian Science Fund
- Hadassah Medical Center
- Israel Science Foundation
- United States Army
- University of Vienna