4V3P

The molecular structure of the left-handed supra-molecular helix of eukaryotic polyribosomes

This is a non-PDB format compatible entry.

Summary for 4V3P

• Entry DOI: 10.2210/pdb4v3p/pdb
• EMDB information: 2790
• Descriptor: G protein beta subunit, 40S ribosomal protein S23, 40S ribosomal protein S18, ... (84 entities in total)
• Functional Keywords: ribosome
• Biological source: Triticum aestivum (bread wheat); More
• Total number of polymer chains: 87
• Total formula weight: 3001444.59

Authors

Myasnikov, A.G.,Afonina, Z.A.,Menetret, J.F.,Shirokov, V.A.,Spirin, A.S.,Klaholz, B.P. (deposition date: 2014-10-20, release date: 2015-04-22, Last modification date: 2019-12-18)

Primary citation

Myasnikov, A.G.,Afonina, Z.A.,Menetret, J.F.,Shirokov, V.A.,Spirin, A.S.,Klaholz, B.P.
The molecular structure of the left-handed supra-molecular helix of eukaryotic polyribosomes.
Nat Commun, 5:5294-5294, 2014

PubMed Abstract: During protein synthesis, several ribosomes bind to a single messenger RNA (mRNA) forming large macromolecular assemblies called polyribosomes. Here we report the detailed molecular structure of a 100 MDa eukaryotic poly-ribosome complex derived from cryo electron tomography, sub-tomogram averaging and pseudo-atomic modelling by crystal structure fitting. The structure allowed the visualization of the three functional parts of the polysome assembly, the central core region that forms a rather compact left-handed supra-molecular helix, and the more open regions that harbour the initiation and termination sites at either ends. The helical region forms a continuous mRNA channel where the mRNA strand bridges neighbouring exit and entry sites of the ribosomes and prevents mRNA looping between ribosomes. This structure provides unprecedented insights into protein- and RNA-mediated inter-ribosome contacts that involve conserved sites through 40S subunits and long protruding RNA expansion segments, suggesting a role in stabilizing the overall polyribosomal assembly.

PubMed: 25376914
DOI: 10.1038/ncomms6294

Experimental method

ELECTRON MICROSCOPY (34 Å)