title: An unexpected type of ribosomes induced by kasugamycin: a look into ancestral times of protein synthesis?
abstract: Translation of leaderless mRNAs, lacking ribosomal recruitment signals other than the 5'-terminal AUG-initiating codon, occurs in all three domains of life. Contemporary leaderless mRNAs may therefore be viewed as molecular fossils resembling ancestral mRNAs. Here, we analyzed the phenomenon of sustained translation of a leaderless mRNA in the presence of the antibiotic kasugamycin. Unexpected from the known in vitro effects of the drug, kasugamycin induced the formation of stable approximately 61S ribosomes in vivo, which were proficient in selectively translating leaderless mRNA. 61S particles are devoid of more than six proteins of the small subunit, including the functionally important proteins S1 and S12. The lack of these proteins could be reconciled with structural changes in the 16S rRNA. These studies provide in vivo evidence for the functionality of ribosomes devoid of multiple proteins and shed light on the evolutionary history of ribosomes.
authors.affiliation: Max F. Perutz Laboratories, Department of Microbiology and Immunobiology, University Departments at the Vienna Biocenter, Vienna, Austria.
authors.forename: Anna Chao
authors.initials: AC
authors.lastname: Kaberdina
authors.forename: Witold
authors.initials: W
authors.lastname: Szaflarski
authors.forename: Knud H
authors.initials: KH
authors.lastname: Nierhaus
authors.forename: Isabella
authors.initials: I
authors.lastname: Moll
mesh_terms: D000617:Aminoglycosides / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008954:Models, Biological; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D010442:Peptide Chain Initiation, Translational / Q000187:drug effects; D014176:Protein Biosynthesis / Q000187:drug effects*; D011487:Protein Conformation; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism; D012336:RNA, Ribosomal, 16S / Q000737:chemistry / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D000617:Aminoglycosides; D000900:Anti-Bacterial Agents; D029968:Escherichia coli Proteins; D012329:RNA, Bacterial; D012336:RNA, Ribosomal, 16S; C100305:kasugamycin