3b31

Publication Abstract from PubMed

Internal ribosome entry site (IRES) RNAs initiate protein synthesis in eukaryotic cells by a noncanonical cap-independent mechanism. IRESes are critical for many pathogenic viruses, but efforts to understand their function are complicated by the diversity of IRES sequences as well as by limited high-resolution structural information. The intergenic region (IGR) IRESes of the Dicistroviridae viruses are powerful model systems to begin to understand IRES function. Here we present the crystal structure of a Dicistroviridae IGR IRES domain that interacts with the ribosome's decoding groove. We find that this RNA domain precisely mimics the transfer RNA anticodon-messenger RNA codon interaction, and its modeled orientation on the ribosome helps explain translocation without peptide bond formation. When combined with a previous structure, this work completes the first high-resolution description of an IRES RNA and provides insight into how RNAs can manipulate complex biological machines.

tRNA-mRNA mimicry drives translation initiation from a viral IRES.,Costantino DA, Pfingsten JS, Rambo RP, Kieft JS Nat Struct Mol Biol. 2008 Jan;15(1):57-64. Epub 2007 Dec 23. PMID:18157151^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.