6p4h
Structure of a mammalian small ribosomal subunit in complex with the Israeli Acute Paralysis Virus IRES (Class 2)
Structural highlights
FunctionRSSA_RABIT Required for the assembly and/or stability of the 40S ribosomal subunit (PubMed:23873042, PubMed:25601755). Required for the processing of the 20S rRNA-precursor to mature 18S rRNA in a late step of the maturation of 40S ribosomal subunits (PubMed:23873042, PubMed:25601755). Also functions as a cell surface receptor for laminin (By similarity). Plays a role in cell adhesion to the basement membrane and in the consequent activation of signaling transduction pathways (By similarity). May play a role in cell fate determination and tissue morphogenesis (By similarity). Also acts as a receptor for several other ligands, including the pathogenic prion protein, viruses, and bacteria. Acts as a PPP1R16B-dependent substrate of PPP1CA (By similarity).[HAMAP-Rule:MF_03016][1] [2] Publication Abstract from PubMedColony collapse disorder (CCD) is a multi-faceted syndrome decimating bee populations worldwide, and a group of viruses of the widely distributed Dicistroviridae family have been identified as a causing agent of CCD. This family of viruses employs non-coding RNA sequences, called internal ribosomal entry sites (IRESs), to precisely exploit the host machinery for viral protein production. Using single-particle cryo-electron microscopy (cryo-EM), we have characterized how the IRES of Israeli acute paralysis virus (IAPV) intergenic region captures and redirects translating ribosomes toward viral RNA messages. We reconstituted two in vitro reactions targeting a pre-translocation and a post-translocation state of the IAPV-IRES in the ribosome, allowing us to identify six structures using image processing classification methods. From these, we reconstructed the trajectory of IAPV-IRES from the early small subunit recruitment to the final post-translocated state in the ribosome. An early commitment of IRES/ribosome complexes for global pre-translocation mimicry explains the high efficiency observed for this IRES. Efforts directed toward fighting CCD by targeting the IAPV-IRES using RNA-interference technology are underway, and the structural framework presented here may assist in further refining these approaches. The Israeli acute paralysis virus IRES captures host ribosomes by mimicking a ribosomal state with hybrid tRNAs.,Acosta-Reyes F, Neupane R, Frank J, Fernandez IS EMBO J. 2019 Oct 14:e102226. doi: 10.15252/embj.2019102226. PMID:31609474[3] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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