title: The bacterial toxin RelE displays codon-specific cleavage of mRNAs in the ribosomal A site.
abstract: The Escherichia coli relBE operon encodes a toxin-antitoxin pair, RelE-RelB. RelB can reverse inhibition of protein synthesis by RelE in vivo. We have found that although RelE does not degrade free RNA, it cleaves mRNA in the ribosomal A site with high codon specificity. Among stop codons UAG is cleaved with fast, UAA intermediate and UGA slow rate, while UCG and CAG are cleaved most rapidly among sense codons. We suggest that inhibition of protein synthesis by RelE is reversed with the help of tmRNA, and that RelE plays a regulatory role in bacteria during adaptation to poor growth conditions.
authors.affiliation: Department of Biochemistry and Molecular Biology, OU, University of Southern Denmark, Campusvej 55, DK-5230 Odense, Denmark.
authors.forename: Kim
authors.initials: K
authors.lastname: Pedersen
authors.forename: Andrey V
authors.initials: AV
authors.lastname: Zavialov
authors.forename: Michael Yu
authors.initials: MY
authors.lastname: Pavlov
authors.forename: Johan
authors.initials: J
authors.lastname: Elf
authors.forename: Kenn
authors.initials: K
authors.lastname: Gerdes
authors.forename: Måns
authors.initials: M
authors.lastname: Ehrenberg
mesh_terms: D001427:Bacterial Toxins / Q000378:metabolism*; D002384:Catalysis; D003062:Codon; D018388:Codon, Terminator; D004926:Escherichia coli / Q000235:genetics; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005798:Genes, Bacterial / Q000235:genetics; D066298:In Vitro Techniques; D008957:Models, Genetic; D009876:Operon; D010452:Peptide Biosynthesis; D014176:Protein Biosynthesis; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism*; D013489:Suppression, Genetic; D013997:Time Factors
chemical_list: D001427:Bacterial Toxins; D003062:Codon; D018388:Codon, Terminator; D029968:Escherichia coli Proteins; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; C465566:RelE protein, E coli; D012269:Ribosomal Proteins; C016700:ribosomal protein L7-L12