4D5N

Cryo-EM structures of ribosomal 80S complexes with termination factors and cricket paralysis virus IRES reveal the IRES in the translocated state

Summary for 4D5N

• Entry DOI: 10.2210/pdb4d5n/pdb
• Related: 4D5L 4D5Y 4D61 4D66 4D67 4D68
• EMDB information: 2810
• Descriptor: EUKARYOTIC PEPTIDE CHAIN RELEASE FACTOR SUBUNIT 1, CRICKET PARALYSIS VIRUS IRES RNA (2 entities in total)
• Functional Keywords: ribosome-rna complex, crpv ires, ribosome, termination, release factors, ribosome/rna
• Biological source: HOMO SAPIENS (HUMAN); More
• Cellular location: Cytoplasm: P62495
• Total number of polymer chains: 2
• Total formula weight: 113404.62

Authors

Muhs, M.,Hilal, T.,Mielke, T.,Skabkin, M.A.,Sanbonmatsu, K.Y.,Pestova, T.V.,Spahn, C.M.T. (deposition date: 2014-11-06, release date: 2015-02-04, Last modification date: 2024-05-08)

Primary citation

Muhs, M.,Hilal, T.,Mielke, T.,Skabkin, M.A.,Sanbonmatsu, K.Y.,Pestova, T.V.,Spahn, C.M.T.
Cryo-Em of Ribosomal 80S Complexes with Termination Factors Reveals the Translocated Cricket Paralysis Virus Ires.
Mol.Cell, 57:422-, 2015

PubMed Abstract: The cricket paralysis virus (CrPV) uses an internal ribosomal entry site (IRES) to hijack the ribosome. In a remarkable RNA-based mechanism involving neither initiation factor nor initiator tRNA, the CrPV IRES jumpstarts translation in the elongation phase from the ribosomal A site. Here, we present cryoelectron microscopy (cryo-EM) maps of 80S⋅CrPV-STOP ⋅ eRF1 ⋅ eRF3 ⋅ GMPPNP and 80S⋅CrPV-STOP ⋅ eRF1 complexes, revealing a previously unseen binding state of the IRES and directly rationalizing that an eEF2-dependent translocation of the IRES is required to allow the first A-site occupation. During this unusual translocation event, the IRES undergoes a pronounced conformational change to a more stretched conformation. At the same time, our structural analysis provides information about the binding modes of eRF1 ⋅ eRF3 ⋅ GMPPNP and eRF1 in a minimal system. It shows that neither eRF3 nor ABCE1 are required for the active conformation of eRF1 at the intersection between eukaryotic termination and recycling.

PubMed: 25601755
DOI: 10.1016/J.MOLCEL.2014.12.016

Experimental method

ELECTRON MICROSCOPY (9 Å)