Article ID Journal Published Year Pages File Type
3425602 Virology 2008 6 Pages PDF
Abstract

West Nile virus methyltransferase catalyzes N7 and 2′-O methylations of the viral RNA cap (GpppA-RNA → m7GpppAm-RNA). The two methylation events are independent, as evidenced by efficient N7 methylation of GpppA-RNA → m7GpppA-RNA and GpppAm-RNA → m7GpppAm-RNA, and by the 2′-O methylation of GpppA-RNA → GpppAm-RNA and m7GpppA-RNA → m7GpppAm-RNA. However, the 2′-O methylation activity prefers substrate m7GpppA-RNA to GpppA-RNA, thereby determining the dominant methylation pathway as GpppA-RNA → m7GpppA-RNA → m7GpppAm-RNA. Mutant enzymes with different methylation defects can trans complement one another in vitro. Furthermore, sequential treatment of GpppA-RNA with distinct methyltransferase mutants generates fully methylated m7GpppAm-RNA, demonstrating that separate molecules of the enzyme can independently catalyze the two cap methylations in vitro.

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Life Sciences Immunology and Microbiology Virology
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