A Three-Stemmed mRNA Pseudoknot in the SARS Coronavirus Frameshift Signal

摘要: A wide range of RNA viruses use programmed -1 ribosomal frameshifting for the production viral fusion proteins. Inspection overlap regions between ORF1a and ORF1b SARS-CoV genome revealed that, similar to all coronaviruses, a frameshift could be used by virus produce protein. Computational analyses signal predicted presence an mRNA pseudoknot containing three double-stranded stem structures rather than two. Phylogenetic showed conservation potential three-stemmed pseudoknots in signals other coronaviruses GenBank database. Though structure is supported nuclease mapping two-dimensional nuclear magnetic resonance studies, our findings suggest that interactions may result local distortions A-form RNA. These are particularly evident vicinity A-bulges stems 2 3. In vitro vivo assays functionally signals: it promotes efficient standard assay systems, sensitive drug genetic mutation known affect efficiency yeast virus. Mutagenesis studies reveal both specific sequences 3 important frameshifting. We have identified new structural motif capable promoting The high degree among suggests this presents novel target antiviral therapeutics.