4D5L

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

Summary for 4D5L

• Entry DOI: 10.2210/pdb4d5l/pdb
• Related: 4D5N 4D5Y 4D61 4D66 4D67 4D68
• EMDB information: 2810
• Descriptor: 18S RRNA 2, 40S RIBOSOMAL PROTEIN ES8, 40S RIBOSOMAL PROTEIN US4, ... (34 entities in total)
• Functional Keywords: crpv ires, ribosome, termination, release factors
• Biological source: ORYCTOLAGUS CUNICULUS (RABBIT); More
• Cellular location: Cytoplasm : G1SS70
• Total number of polymer chains: 34
• Total formula weight: 1221711.59

Authors

Muhs, M.,Hilal, T.,Mielke, T.,Skabkin, M.A.,Sanbonmatsu, K.Y.,Pestova, T.V.,Spahn, C.M.T. (deposition date: 2014-11-05, release date: 2015-02-04, Last modification date: 2017-08-23)

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)