title: Selective translation of leaderless mRNAs by specialized ribosomes generated by MazF in Escherichia coli.
abstract: Escherichia coli (E. coli) mazEF is a stress-induced toxin-antitoxin (TA) module. The toxin MazF is an endoribonuclease that cleaves single-stranded mRNAs at ACA sequences. Here, we show that MazF cleaves at ACA sites at or closely upstream of the AUG start codon of some specific mRNAs and thereby generates leaderless mRNAs. Moreover, we provide evidence that MazF also targets 16S rRNA within 30S ribosomal subunits at the decoding center, thereby removing 43 nucleotides from the 3' terminus. As this region comprises the anti-Shine-Dalgarno (aSD) sequence that is required for translation initiation on canonical mRNAs, a subpopulation of ribosomes is formed that selectively translates the described leaderless mRNAs both in vivo and in vitro. Thus, we have discovered a modified translation machinery that is generated in response to MazF induction and that probably serves for stress adaptation in Escherichia coli.
authors.affiliation: Max F. Perutz Laboratories, Center for Molecular Biology, Department of Microbiology, Immunobiology and Genetics, University of Vienna, Dr. Bohrgasse 9/4, 1030 Vienna, Austria.
authors.forename: Oliver
authors.initials: O
authors.lastname: Vesper
authors.forename: Shahar
authors.initials: S
authors.lastname: Amitai
authors.forename: Maria
authors.initials: M
authors.lastname: Belitsky
authors.forename: Konstantin
authors.initials: K
authors.lastname: Byrgazov
authors.forename: Anna Chao
authors.initials: AC
authors.lastname: Kaberdina
authors.forename: Hanna
authors.initials: H
authors.lastname: Engelberg-Kulka
authors.forename: Isabella
authors.initials: I
authors.lastname: Moll
mesh_terms: D001483:Base Sequence; D018387:Codon, Initiator; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004722:Endoribonucleases / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D015964:Gene Expression Regulation, Bacterial; D008958:Models, Molecular; D008969:Molecular Sequence Data; D014176:Protein Biosynthesis; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000378:metabolism; D012269:Ribosomal Proteins / Q000235:genetics; D054680:Ribosome Subunits, Small, Bacterial / Q000378:metabolism*; D013312:Stress, Physiological
chemical_list: D018387:Codon, Initiator; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C422955:MazF protein, E coli; D012329:RNA, Bacterial; D012333:RNA, Messenger; D012336:RNA, Ribosomal, 16S; D012269:Ribosomal Proteins; C459789:YfiD protein, E coli; C032643:ribosomal protein S21; D004722:Endoribonucleases