Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6142389 | Virus Research | 2014 | 8 Pages |
Abstract
Pepino mosaic virus (PepMV) is a mechanically-transmitted positive-strand RNA potexvirus, with a 6410Â nt long single-stranded (ss) RNA genome flanked by a 5â²-methylguanosine cap and a 3â² poly-A tail. Computer-assisted folding of the 64Â nt long PepMV 3â²-untranslated region (UTR) resulted in the prediction of three stem-loop structures (hp1, hp2, and hp3 in the 3â²-5â² direction). The importance of these structures and/or sequences for promotion of negative-strand RNA synthesis and binding to the RNA dependent RNA polymerase (RdRp) was tested in vitro using a specific RdRp assay. Hp1, which is highly variable among different PepMV isolates, appeared dispensable for negative-strand synthesis. Hp2, which is characterized by a large U-rich loop, tolerated base-pair changes in its stem as long as they maintained the stem integrity but was very sensitive to changes in the U-rich loop. Hp3, which harbours the conserved potexvirus ACUUAA hexamer motif, was essential for template activity. Template-RNA polymerase binding competition experiments showed that the ACUUAA sequence represents a high-affinity RdRp binding element.
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Authors
Toba A.M. Osman, René C.L. Olsthoorn, Ioannis C. Livieratos,