Article ID Journal Published Year Pages File Type
6141596 Virology 2010 11 Pages PDF
Abstract
We report that dengue virus (DENV) methyltransferase sequentially methylates the guanine N-7 and ribose 2′-O positions of viral RNA cap (GpppA→m7GpppA→m7GpppAm). The order of two methylations is determined by the preference of 2′-O methylation for substrate m7GpppA-RNA to GpppA-RNA, and the 2′-O methylation is not absolutely dependent on the prior N-7 methylation. A mutation that completely abolished the 2′-O methylation attenuated DENV replication in cell culture, whereas another mutation that abolished both methylations was lethal for viral replication, suggesting that N-7 methylation is more important than 2′-O methylation in viral replication. The latter mutant with lethal replication could be rescued by trans complementation using a wild-type DENV replicon. Furthermore, we found that chimeric DENVs containing the West Nile virus methyltransferase, polymerase, or full-length NS5 were nonreplicative, but the replication defect could also be rescued through trans complementation using the wild-type DENV replicon.
Related Topics
Life Sciences Immunology and Microbiology Virology
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