Structural basis for ribosome recruitment and manipulation by a viral IRES RNA.
Canonical cap-dependent translation initiation requires a large number of protein factors that act in a stepwise assembly process. In contrast, internal ribosomal entry sites (IRESs) are cis-acting RNAs that in some cases completely supplant these factors by recruiting and activating the ribosome using a single structured RNA. Here we present the crystal structures of the ribosome-binding domain from a Dicistroviridae intergenic region IRES at 3.1 angstrom resolution, providing a view of the prefolded architecture of an all-RNA translation initiation apparatus. Docking of the structure into cryo-electron microscopy reconstructions of an IRES-ribosome complex suggests a model for ribosome manipulation by a dynamic IRES RNA.
Pfingsten
Jennifer S
JS
Department of Biochemistry and Molecular Genetics, University of Colorado at Denver and Health Sciences Center, Mail Stop 8101, Post Office Box 6511, Aurora, CO 80045, USA.
Costantino
David A
DA
Kieft
Jeffrey S
JS
D001665:Binding Sites; D020285:Cryoelectron Microscopy; D003460:Crystallization; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009154:Mutation; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012328:RNA Viruses / Q000235:genetics*; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D038621:Regulatory Sequences, Ribonucleic Acid / Q000235:genetics; D012270:Ribosomes / Q000378:metabolism*
D012367:RNA, Viral; D038621:Regulatory Sequences, Ribonucleic Acid