Many viruses add a cap structure at the 5’ end of their RNAs. This structure is essential for the translation of mRNA into proteins. In addition, the cap structure lures the detection of foreign RNA by innate immunity sensors. The addition of the cap structure by viral enzymes is probably coupled to the polymerization process. While some viruses steal caps from cellular RNAs in a process called "cap snatching", many viruses encode multi-enzymatic machineries catalyzing the synthesis of these structures. The laboratory has recently developed all the necessary tools needed for the monitoring of RNA triphosphatase, guanylyltransferase and methyltransferase activities. We particularly focus on the specific synthesis of these cap structures in the genera Flavivirus, Coronavirus and Alphavirus; with the prototypic members being dengue, SARS and Chikungunya viruses, respectively.
- Mechanism of cap structure synthesis
