EMD-12065
Yeast 80S ribosome with bound A/P- and P/E-tRNAs (PRE-4)
EMD-12065
Single-particle3.3 Å
Deposition: 09/12/2020Map released: 10/03/2021
Last modified: 07/07/2021
Sample Organism:
Saccharomyces cerevisiae
Sample: Cryo-EM structure of the S. cerevisiae 80S ribosome in complex with eEF3 and P/P- and E/E-site tRNAs.
Deposition Authors: Ranjan N, Pochopien AA, Wu CC, Beckert B, Blanchet S, Green R, Rodnina MV, Wilson DN
Sample: Cryo-EM structure of the S. cerevisiae 80S ribosome in complex with eEF3 and P/P- and E/E-site tRNAs.
Deposition Authors: Ranjan N, Pochopien AA, Wu CC, Beckert B, Blanchet S, Green R, Rodnina MV, Wilson DN
Yeast translation elongation factor eEF3 promotes late stages of tRNA translocation.
Ranjan N 
,
Pochopien AA,
Chih-Chien Wu C,
Beckert B,
Blanchet S ,
Green R ,
V Rodnina M ,
Wilson DN
(2021) Embo J. , 40 , e106449 - e106449
,
Pochopien AA,
Chih-Chien Wu C,
Beckert B,
Blanchet S ,
Green R ,
V Rodnina M ,
Wilson DN
(2021) Embo J. , 40 , e106449 - e106449
Abstract:
In addition to the conserved translation elongation factors eEF1A and eEF2, fungi require a third essential elongation factor, eEF3. While eEF3 has been implicated in tRNA binding and release at the ribosomal A and E sites, its exact mechanism of action is unclear. Here, we show that eEF3 acts at the mRNA-tRNA translocation step by promoting the dissociation of the tRNA from the E site, but independent of aminoacyl-tRNA recruitment to the A site. Depletion of eEF3 in vivo leads to a general slowdown in translation elongation due to accumulation of ribosomes with an occupied A site. Cryo-EM analysis of native eEF3-ribosome complexes shows that eEF3 facilitates late steps of translocation by favoring non-rotated ribosomal states, as well as by opening the L1 stalk to release the E-site tRNA. Additionally, our analysis provides structural insights into novel translation elongation states, enabling presentation of a revised yeast translation elongation cycle.
In addition to the conserved translation elongation factors eEF1A and eEF2, fungi require a third essential elongation factor, eEF3. While eEF3 has been implicated in tRNA binding and release at the ribosomal A and E sites, its exact mechanism of action is unclear. Here, we show that eEF3 acts at the mRNA-tRNA translocation step by promoting the dissociation of the tRNA from the E site, but independent of aminoacyl-tRNA recruitment to the A site. Depletion of eEF3 in vivo leads to a general slowdown in translation elongation due to accumulation of ribosomes with an occupied A site. Cryo-EM analysis of native eEF3-ribosome complexes shows that eEF3 facilitates late steps of translocation by favoring non-rotated ribosomal states, as well as by opening the L1 stalk to release the E-site tRNA. Additionally, our analysis provides structural insights into novel translation elongation states, enabling presentation of a revised yeast translation elongation cycle.