title: Mechanism of eIF6-mediated inhibition of ribosomal subunit joining.
abstract: During the process of ribosomal assembly, the essential eukaryotic translation initiation factor 6 (eIF6) is known to act as a ribosomal anti-association factor. However, a molecular understanding of the anti-association activity of eIF6 is still missing. Here we present the cryo-electron microscopy reconstruction of a complex of the large ribosomal subunit with eukaryotic eIF6 from Saccharomyces cerevisiae. The structure reveals that the eIF6 binding site involves mainly rpL23 (L14p in Escherichia coli). Based on our structural data, we propose that the mechanism of the anti-association activity of eIF6 is based on steric hindrance of intersubunit bridge formation around the dynamic bridge B6.
authors.affiliation: Department of Biochemistry, Gene Center and Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Gartmann
authors.affiliation: Institut für Biochemie der Charité, Humboldt Universität Berlin, Monbijoustrasse 2, 10117 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Blau
authors.affiliation: Department of Biochemistry, Gene Center and Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Armache
authors.affiliation: UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin; Institut für Medizinische Physik und Biophysik, Charité, Ziegelstrasse 5-9, 10098 Berlin, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Mielke
authors.affiliation: Institute of Structural and Molecular Biology, School of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX, United Kingdom.
authors.forename: Maya
authors.initials: M
authors.lastname: Topf
authors.affiliation: Department of Biochemistry, Gene Center and Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany. Electronic address: beckmann@lmb.uni-muenchen.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Beckmann
mesh_terms: D008854:Microscopy, Electron; D008958:Models, Molecular; D010448:Peptide Initiation Factors / Q000737:chemistry / Q000502:physiology*; D011487:Protein Conformation; D012270:Ribosomes / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*
chemical_list: D010448:Peptide Initiation Factors; D029701:Saccharomyces cerevisiae Proteins; C021019:eIF-6