Fig. 1.

Genome structure of USUV: C = capsid protein/capsid protein; prM = precursor of the membrane proteins; E = surface glycoprotein (envelope protein); NS = non-structural protein; UTR = non-translated region; Cap = structure at 5′ end; NS1 = inhibitor of signal transduction for innate immunity; NS2-NS2A = required for virus assembly and inhibitor of activation of the IFN-β promoter; NS3 = multifunctional protein: serine protease (co-factor NS2B), 5′-RNA-triphosphatase (RTPase), nucleoside-triphosphatase (NTPase) and ATP-dependent RNA helicase; NS4-NS4A = modifies the endoplasmic reticulum, NS4B blocks IFN response; NS5 = RNA-dependent RNA polymerase, N-7- and 2′O-methyltransferase (MTase) for methylation of the 5′-RNA-cap structure.