8SUP
Structure of the 48S translation initiation complex assembled on the encephalomyocarditis virus IRES
This is a non-PDB format compatible entry.
Summary for 8SUP
| Entry DOI | 10.2210/pdb8sup/pdb |
| EMDB information | 40774 |
| Descriptor | Eukaryotic translation initiation factor 3 subunit A, EMCV mRNA, Eukaryotic translation initiation factor 1A, X-chromosomal, ... (48 entities in total) |
| Functional Keywords | emcv, ires, cryo-em, 40sic, ribosome |
| Biological source | Oryctolagus cuniculus (rabbit) More |
| Total number of polymer chains | 47 |
| Total formula weight | 1893877.12 |
| Authors | Bhattacharjee, S.,Abaeva, I.S.,Brown, Z.P.,Arhab, Y.,Fallah, H.,Jeevan, J.C.,Hellen, C.U.T.,Frank, J.,Pestova, T.V. (deposition date: 2023-05-12, release date: 2026-03-18) |
| Primary citation | Bhattacharjee, S.,Abaeva, I.S.,Brown, Z.P.,Arhab, Y.,Fallah, H.,Hellen, C.U.T.,Frank, J.,Pestova, T.V. The mechanism of ribosomal recruitment during translation initiation on Type 2 IRESs. Biorxiv, 2025 Cited by PubMed Abstract: The encephalomyocarditis virus (EMCV) IRES and other Type 2 IRESs comprise domains H-L and specifically interact with eIF4G/eIF4A through their essential JK domain. However, the JK domain is not sufficient for IRES function, which also requires the preceding domain I of unknown function. To identify interactions that drive ribosomal recruitment of eIF4G/eIF4A-bound Type 2 IRESs, we determined the cryo-EM structure of 48S initiation complexes formed on the EMCV IRES. It revealed that the apical domain I cloverleaf contacts ribosomal proteins uS13 and uS19 via its Id subdomain and that the essential GNRA tetraloop in subdomain Ic interacts directly with the TψC domain of initiator tRNA. Functional assays supported the exceptional role of these interactions for initiation on this IRES. The strong conservation of primary and secondary structures of the apex of domain I among Type 2 IRESs suggests that the reported interactions are a common essential feature of them all. PubMed: 40568087DOI: 10.1101/2025.06.11.659010 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.1 Å) |
Structure validation
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