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THE REACTIVITY OF THE 5′ tRNA‐LIKE MOTIF OF THE HEPATITIS C VIRUS REVEALS ALTERNATE STRUCTURES OF THE INTERNAL RIBOSOME ENTRY SITE
Author(s) -
Birk Alexander Victor,
Beguiristan Nerea,
Chorden Tsering,
Robertson Hugh D,
Gomez Jordi
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.4.a69-b
Subject(s) - internal ribosome entry site , rnase p , biology , nucleic acid structure , rna , translation (biology) , ribosome , transfer rna , eukaryotic translation , virology , genetics , computational biology , microbiology and biotechnology , messenger rna , gene
Hepatitis C virus (HCV) is a major cause of liver chronic diseases. Genomic HCV RNA translation initiates within the highly structured and conserved internal ribosome entry site (IRES). Long‐range annealing (LRA) of 5′‐ and 3′‐ flanking regions of IRES was previously demonstrated using RNase III. The role of this annealing in regulation of HCV IRES structure is unknown. Here we provide the first direct evidence that the structure of the HCV IRES, specifically stem‐loop III and IV, can be regulatedby the LRA. The IRES structural transitions were detected based on an ability of RNase P to recognize stem‐loops III and IV as a substrate. Both prokaryotic and human RNase P were used in our experiments. First, ribo‐and deoxy‐oligonucleotides (0.0015‐1.5 μM) complementary to the 5′‐sequence of LRA (22–44), specifically inhibited RNase Preactions. Furthermore, removal of first 5′ 36 nucleotides attenuated RNase P the reactions. Thus, LRA is responsible for an IRES structure that provides optimum recognition of stem‐loop III and IV by RNase P. The structural specificity and accessibility are lost when the annealing is impaired. The ability to detect and control the structural transitions within the IRES opens new possibilities to regulate HCV translation and replication, and to promote the development of new antiviral therapeutics.