Figure 1: Alphavirus genome organization. Organization of the alphaviurs genome is shown. The genomic RNA has a methyl guanine cap (mG), and a polyadenylated tail (An). The mRNA encoding the structural proteins is transcribed from a replication intermediate (not shown) and the 26S subgenomic RNA promoter. Cleavage events (carried out by viral and host proteases) produce mature, individual structural proteins from the initially translated polyprotein.