title: Structure of the E. coli ribosome-EF-Tu complex at <3 Å resolution by Cs-corrected cryo-EM.
abstract: Single particle electron cryomicroscopy (cryo-EM) has recently made significant progress in high-resolution structure determination of macromolecular complexes due to improvements in electron microscopic instrumentation and computational image analysis. However, cryo-EM structures can be highly non-uniform in local resolution and all structures available to date have been limited to resolutions above 3 Å. Here we present the cryo-EM structure of the 70S ribosome from Escherichia coli in complex with elongation factor Tu, aminoacyl-tRNA and the antibiotic kirromycin at 2.65-2.9 Å resolution using spherical aberration (Cs)-corrected cryo-EM. Overall, the cryo-EM reconstruction at 2.9 Å resolution is comparable to the best-resolved X-ray structure of the E. coli 70S ribosome (2.8 Å), but provides more detailed information (2.65 Å) at the functionally important ribosomal core. The cryo-EM map elucidates for the first time the structure of all 35 rRNA modifications in the bacterial ribosome, explaining their roles in fine-tuning ribosome structure and function and modulating the action of antibiotics. We also obtained atomic models for flexible parts of the ribosome such as ribosomal proteins L9 and L31. The refined cryo-EM-based model presents the currently most complete high-resolution structure of the E. coli ribosome, which demonstrates the power of cryo-EM in structure determination of large and dynamic macromolecular complexes.
authors.affiliation: 3D Electron Cryomicroscopy Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Niels
authors.initials: N
authors.lastname: Fischer
authors.affiliation: Abteilung Molekulare Strukturbiologie, Institut für Mikrobiologie und Genetik, GZMB, Georg-August Universität Göttingen, Justus-von Liebig Weg 11, 37077 Göttingen, Germany.
authors.forename: Piotr
authors.initials: P
authors.lastname: Neumann
authors.affiliation: 1] Molecular and Radiation Biophysics Department, B.P. Konstantinov Petersburg Nuclear Physics Institute of National Research Centre 'Kurchatov Institute', 188300 Gatchina, Russia [2] St Petersburg Polytechnic University, Polytechnicheskaya, 29, 195251 St Petersburg, Russia [3] Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Andrey L
authors.initials: AL
authors.lastname: Konevega
authors.affiliation: Department of Theoretical and Computational Biophysics, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Lars V
authors.initials: LV
authors.lastname: Bock
authors.affiliation: Abteilung Molekulare Strukturbiologie, Institut für Mikrobiologie und Genetik, GZMB, Georg-August Universität Göttingen, Justus-von Liebig Weg 11, 37077 Göttingen, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Ficner
authors.affiliation: Department of Physical Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany.
authors.forename: Marina V
authors.initials: MV
authors.lastname: Rodnina
authors.affiliation: 1] 3D Electron Cryomicroscopy Group, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany [2] Department of 3D Electron Cryomicroscopy, Institute of Microbiology and Genetics, Georg-August Universität, 37077 Göttingen, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Stark
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism; D020285:Cryoelectron Microscopy / Q000379:methods; D004926:Escherichia coli / Q000737:chemistry* / Q000648:ultrastructure*; D008024:Ligands; D008958:Models, Molecular; D010444:Peptide Elongation Factor Tu / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*; D011728:Pyridones / Q000737:chemistry / Q000378:metabolism; D012329:RNA, Bacterial / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D012335:RNA, Ribosomal / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D012343:RNA, Transfer / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D012270:Ribosomes / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure*
chemical_list: D000900:Anti-Bacterial Agents; D008024:Ligands; D011728:Pyridones; D012329:RNA, Bacterial; D012335:RNA, Ribosomal; D012343:RNA, Transfer; D010444:Peptide Elongation Factor Tu; C008536:mocimycin