Mechanism of eIF6-mediated inhibition of ribosomal subunit joining.
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.
Gartmann
Marco
M
Department of Biochemistry, Gene Center and Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
Blau
Michael
M
Institut für Biochemie der Charité, Humboldt Universität Berlin, Monbijoustrasse 2, 10117 Berlin, Germany.
Armache
Jean-Paul
JP
Department of Biochemistry, Gene Center and Center for Integrated Protein Science (CiPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich, Germany.
Mielke
Thorsten
T
UltraStrukturNetzwerk, Max Planck Institute for Molecular Genetics, Ihnestrasse 73, 14195 Berlin; Institut für Medizinische Physik und Biophysik, Charité, Ziegelstrasse 5-9, 10098 Berlin, Germany.
Topf
Maya
M
Institute of Structural and Molecular Biology, School of Crystallography, Birkbeck College, University of London, Malet Street, London WC1E 7HX, United Kingdom.
Beckmann
Roland
R
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.
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*
D010448:Peptide Initiation Factors; D029701:Saccharomyces cerevisiae Proteins; C021019:eIF-6