9q2t
NediV IRES in complex with Rabbit 80S ribosome with eEF2 and P site Ala-tRNA
Structural highlights
FunctionRS3_RABIT Component of the small ribosomal subunit (PubMed:23873042, PubMed:25601755, PubMed:26245381, PubMed:27863242). The ribosome is a large ribonucleoprotein complex responsible for the synthesis of proteins in the cell (PubMed:23873042, PubMed:25601755, PubMed:26245381, PubMed:27863242). Has endonuclease activity and plays a role in repair of damaged DNA (By similarity). Cleaves phosphodiester bonds of DNAs containing altered bases with broad specificity and cleaves supercoiled DNA more efficiently than relaxed DNA (By similarity). Displays high binding affinity for 7,8-dihydro-8-oxoguanine (8-oxoG), a common DNA lesion caused by reactive oxygen species (ROS) (By similarity). Has also been shown to bind with similar affinity to intact and damaged DNA (By similarity). Stimulates the N-glycosylase activity of the base excision protein OGG1 (By similarity). Enhances the uracil excision activity of UNG1 (By similarity). Also stimulates the cleavage of the phosphodiester backbone by APEX1 (By similarity). When located in the mitochondrion, reduces cellular ROS levels and mitochondrial DNA damage (By similarity). Has also been shown to negatively regulate DNA repair in cells exposed to hydrogen peroxide (By similarity). Plays a role in regulating transcription as part of the NF-kappa-B p65-p50 complex where it binds to the RELA/p65 subunit, enhances binding of the complex to DNA and promotes transcription of target genes (By similarity). Represses its own translation by binding to its cognate mRNA (By similarity). Binds to and protects TP53/p53 from MDM2-mediated ubiquitination (By similarity). Involved in spindle formation and chromosome movement during mitosis by regulating microtubule polymerization (By similarity). Involved in induction of apoptosis through its role in activation of CASP8 (By similarity). Induces neuronal apoptosis by interacting with the E2F1 transcription factor and acting synergistically with it to up-regulate pro-apoptotic proteins BCL2L11/BIM and HRK/Dp5 (By similarity). Interacts with TRADD following exposure to UV radiation and induces apoptosis by caspase-dependent JNK activation (By similarity).[UniProtKB:P23396][1] [2] [3] [4] Publication Abstract from PubMedWe utilized the nedicistrovirus (NediV) intergenic region (IGR) internal ribosomal entry site (IRES)-mediated, initiation factor-independent translation initiation system and determined high-resolution structures of 80S ribosome complexes with the NediV IRES in various functional states, including binary complexes, aminoacyl-transfer RNA (tRNA)-bound complexes, and complexes with elongation factor eEF2. In binary complexes, the NediV IRES primarily occupies the ribosomal P site, exhibiting conformational flexibility and engaging the ribosome at multiple interaction sites. Upon translocation, the IRES undergoes structural rearrangements, including destabilization of its PKI domain, facilitating the transition to canonical elongation. Crucially, we captured an eEF2-bound complex, along with an eEF1A-bound failed decoding complex featuring a mismatched tRNA, the latter representing the first instance of a canonical elongation complex visualized in the presence of a natural, hydrolysable nucleotide and without the addition of any trapping agents. These findings provide a comprehensive structural overview of IGR IRES-mediated translation initiation and its transition to elongation, revealing key mechanistic details of viral translation and proofreading. Structural studies of nedicistrovirus IRES-driven, initiation factor-independent translation shed light on key steps of eukaryotic translation elongation.,De S, Altomare CG, Abaeva IS, Dadhwal P, Garg P, Acosta-Reyes F, Brown ZP, Pestova TV, Hellen CUT, Frank J Nucleic Acids Res. 2026 May 20;54(10):gkag510. doi: 10.1093/nar/gkag510. PMID:42240621[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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