BACKGROUND: The ribosome is central to protein synthesis in all living organisms. Single-particle electron cryomicroscopy has recently led to the determination of three-dimensional structures of bacterial ribosomes to approximately 20 A, which have since revolutionised our understanding of ribosomal function. The structure we present here of the 80S rat liver ribosome leads the way to similar progress for mammalian ribosomes. RESULTS: Among the new details revealed by our 25 A structure of the 80S rat liver ribosome are channels within the subunits, a large 'flat ribosomal surface' (FRS) on the outer surface of the large subunit and structural extensions of the mammalian compared to the bacterial ribosome. The main large subunit channel in both the bacterial and the mammalian species starts at the peptidyl transferase centre, below the central protuberance, and ends in the FRS, at the lower back of the large subunit. Structurally, the channels of both species can be directly superimposed. CONCLUSIONS: The mammalian structural extensions--none of which trespass the FRS--can be interpreted in terms of rRNA inserts and additional protein content over that of bacterial ribosomes. The main large subunit channel, which ends at the FRS, is the best candidate for the exit channel for proteins targeted for the endoplasmic reticulum.
BACKGROUND: The ribosome is central to protein synthesis in all living organisms. Single-particle electron cryomicroscopy has recently led to the determination of three-dimensional structures of bacterial ribosomes to approximately 20 A, which have since revolutionised our understanding of ribosomal function. The structure we present here of the 80S rat liver ribosome leads the way to similar progress for mammalian ribosomes. RESULTS: Among the new details revealed by our 25 A structure of the 80S rat liver ribosome are channels within the subunits, a large 'flat ribosomal surface' (FRS) on the outer surface of the large subunit and structural extensions of the mammalian compared to the bacterial ribosome. The main large subunit channel in both the bacterial and the mammalian species starts at the peptidyl transferase centre, below the central protuberance, and ends in the FRS, at the lower back of the large subunit. Structurally, the channels of both species can be directly superimposed. CONCLUSIONS: The mammalian structural extensions--none of which trespass the FRS--can be interpreted in terms of rRNA inserts and additional protein content over that of bacterial ribosomes. The main large subunit channel, which ends at the FRS, is the best candidate for the exit channel for proteins targeted for the endoplasmic reticulum.
Authors: M G Gomez-Lorenzo; C M Spahn; R K Agrawal; R A Grassucci; P Penczek; K Chakraburtty; J P Ballesta; J L Lavandera; J F Garcia-Bustos; J Frank Journal: EMBO J Date: 2000-06-01 Impact factor: 11.598
Authors: Jean-Paul Armache; Alexander Jarasch; Andreas M Anger; Elizabeth Villa; Thomas Becker; Shashi Bhushan; Fabrice Jossinet; Michael Habeck; Gülcin Dindar; Sibylle Franckenberg; Viter Marquez; Thorsten Mielke; Michael Thomm; Otto Berninghausen; Birgitta Beatrix; Johannes Söding; Eric Westhof; Daniel N Wilson; Roland Beckmann Journal: Proc Natl Acad Sci U S A Date: 2010-10-27 Impact factor: 11.205
Authors: Alexander Jarasch; Philipp Dziuk; Thomas Becker; Jean-Paul Armache; Andreas Hauser; Daniel N Wilson; Roland Beckmann Journal: Nucleic Acids Res Date: 2011-10-18 Impact factor: 16.971
Authors: Eli O van der Sluis; Heike Bauerschmitt; Thomas Becker; Thorsten Mielke; Jens Frauenfeld; Otto Berninghausen; Walter Neupert; Johannes M Herrmann; Roland Beckmann Journal: Genome Biol Evol Date: 2015-04-09 Impact factor: 3.416