[NMR paper] NMR study of RNA structures in the 3´-end of the Hepatitis C Virus genome.

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NMR study of RNA structures in the 3´-end of the Hepatitis C Virus genome.

Related Articles NMR study of RNA structures in the 3´-end of the Hepatitis C Virus genome.

Biochemistry. 2017 Aug 22;:

Authors: Kranawetter C, Brady S, Sun L, Schroeder M, Chen SJ, Heng X

Abstract
The 3'-end of the genomic RNA of the Hepatitis C virus (HCV) embeds conserved elements that regulate viral RNA synthesis and protein translation by mechanisms that have yet to be elucidated. Previous studies with oligo-RNA fragments have led to multiple, mutually exclusive secondary structure predictions, indicating that HCV RNA structure may be context dependent. Here we employed an NMR approach that involves long-range adenosine interaction detection, coupled with site-specific 2H labeling, to probe the structure of the intact 3´-end of the HCV genome (385 nucleotides). Our data reveal that the 3´-end exists as an equilibrium mixture of two conformations: an open conformation in which the 98-nt of the 3´-tail (3´X) forms a two-stem-loop structure with the kissing-loop residues sequestered, and a closed conformation in which the 3´X rearranges its structure and forms a long-range kissing-loop interaction with an upstream cis-acting element 5BSL3.2. The long-range kissing species is favored under high Mg2+ conditions, and the intervening sequences do not affect the equilibrium as their secondary structures remain unchanged. The open- and closed-conformations are consistent with the reported function regulation of viral RNA synthesis and protein translation, respectively. NMR detection of these RNA conformations and the structural equilibrium in the 3´-end of the HCV genome support its roles in coordinating various steps of HCV replication.


PMID: 28829576 [PubMed - as supplied by publisher]



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