Barria Maria Inés auteur aut IRD Gonzalez A. auteur aut IRD Vera Otarola Jorge auteur aut IRD Leon Ursula auteur aut IRD Vollrath Valeska auteur aut IRD Marsac Delphine auteur aut IRD Monasterio O. auteur aut IRD Pérez Acle T. auteur aut IRD Soza Alejandro auteur aut IRD Lopez Lastra Marcelo auteur aut IRD text journalArticle eng text/pdf born digital access The HCV internal ribosome entry site (IRES) spans a region of similar to 340 nt that encompasses most of the 5' untranslated region (5'UTR) of the viral mRNA and the first 24-40 nt of the core-coding region. To investigate the implication of altering the primary sequence of the 5'UTR on IRES activity, naturally occurring variants of the 5'UTR were isolated from clinical samples and analyzed. The impact of the identified mutations on translation was evaluated in the context of RLuc/FLuc bicistronic RNAs. Results show that depending on their location within the RNA structure, these naturally occurring mutations cause a range of effects on IRES activity. However, mutations within subdomain IIId hinder HCV IRES-mediated translation. In an attempt to explain these data, the dynamic behavior of the subdomain IIId was analyzed by means of molecular dynamics (MD) simulations. Despite the loss of function, MD simulations predicted that mutant G266A/G268U possesses a structure similar to the wt-RNA. This prediction was validated by analyzing the secondary structure of the isolated IIId RNAs by circular dichroism spectroscopy in the presence or absence of Mg2+ ions. These data strongly suggest that the primary sequence of subdomain IIId plays a key role in HCV IRES-mediated translation. specialized 020 052 37 3 957-971 2009 0305-1048 https://www.documentation.ird.fr/hor/fdi:010044331 10.1093/nar/gkn1022 0305-1048 [F B010044331] https://www.documentation.ird.fr/hor/fdi:010044331 https://www.documentation.ird.fr/intranet/publi/2009/03/010044331.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2009-04-08 2017-08-23 fdi:010044331 fre