7syv

Structure of the wt IRES eIF5B-containing pre-48S initiation complex, open conformation. Structure 14(wt)

spinqualitylabelsall models 7syv, resolution 3.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 7syv is a 10 chain structure with sequence from Homo sapiens and Oryctolagus cuniculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: Electron Microscopy, Resolution 3.9Å Ligands: GTP, MG, NA, ZN Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function G1T3D8_RABIT Publication Abstract from PubMed Hepatitis C virus mRNA contains an internal ribosome entry site (IRES) that mediates end-independent translation initiation, requiring a subset of eukaryotic initiation factors (eIFs). Biochemical studies revealed that direct binding of the IRES to the 40S ribosomal subunit places the initiation codon into the P site, where it base pairs with eIF2-bound Met-tRNAiMet forming a 48S initiation complex. Subsequently, eIF5 and eIF5B mediate subunit joining, yielding an elongation-competent 80S ribosome. Initiation can also proceed without eIF2, in which case Met-tRNAiMet is recruited directly by eIF5B. However, the structures of initiation complexes assembled on the HCV IRES, the transitions between different states, and the accompanying conformational changes have remained unknown. To fill these gaps, we now obtained cryo-EM structures of IRES initiation complexes, at resolutions up to 3.5 A, that cover all major stages from the initial ribosomal association, through eIF2-containing 48S initiation complexes, to eIF5B-containing complexes immediately prior to subunit joining. These structures provide insights into the dynamic network of 40S/IRES contacts, highlight the role of IRES domain II, and reveal conformational changes that occur during the transition from eIF2- to eIF5B-containing 48S complexes and prepare them for subunit joining. Molecular architecture of 40S translation initiation complexes on the hepatitis C virus IRES.,Brown ZP, Abaeva IS, De S, Hellen CUT, Pestova TV, Frank J EMBO J. 2022 Aug 16;41(16):e110581. doi: 10.15252/embj.2022110581. Epub 2022 Jul , 13. PMID:35822879 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ribosome 3D structures

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