6MTB

Rabbit 80S ribosome with P- and Z-site tRNAs (unrotated state)

This is a non-PDB format compatible entry.

Summary for 6MTB

• Entry DOI: 10.2210/pdb6mtb/pdb
• EMDB information: 9234 9235 9236 9237
• Descriptor: mRNA, 60S ribosomal protein L5, 60S ribosomal protein L6, ... (85 entities in total)
• Functional Keywords: ribosome, translation
• Biological source: Oryctolagus cuniculus (Rabbit); More
• Total number of polymer chains: 83
• Total formula weight: 3234941.99

Authors

Brown, A.,Baird, M.R.,Yip, M.C.J.,Murray, J.,Shao, S. (deposition date: 2018-10-19, release date: 2018-11-21, Last modification date: 2019-05-15)

Primary citation

Brown, A.,Baird, M.R.,Yip, M.C.,Murray, J.,Shao, S.
Structures of translationally inactive mammalian ribosomes.
Elife, 7:-, 2018

PubMed Abstract: The cellular levels and activities of ribosomes directly regulate gene expression during numerous physiological processes. The mechanisms that globally repress translation are incompletely understood. Here, we use electron cryomicroscopy to analyze inactive ribosomes isolated from mammalian reticulocytes, the penultimate stage of red blood cell differentiation. We identify two types of ribosomes that are translationally repressed by protein interactions. The first comprises ribosomes sequestered with elongation factor 2 (eEF2) by SERPINE mRNA binding protein 1 (SERBP1) occupying the ribosomal mRNA entrance channel. The second type are translationally repressed by a novel ribosome-binding protein, interferon-related developmental regulator 2 (IFRD2), which spans the P and E sites and inserts a C-terminal helix into the mRNA exit channel to preclude translation. IFRD2 binds ribosomes with a tRNA occupying a noncanonical binding site, the 'Z site', on the ribosome. These structures provide functional insights into how ribosomal interactions may suppress translation to regulate gene expression.

PubMed: 30355441
DOI: 10.7554/eLife.40486

Experimental method

ELECTRON MICROSCOPY (3.6 Å)