Structural Differences Observed in Arboviruses of the Alphavirus and Flavivirus Genera

Figure 2

Alphavirus genome organization. Alphaviruses are organized with the (nonstructural) ns proteins at the 5′ end of the genome The ns proteins are translated from the genomic RNA while the structural proteins are translated from a subgenomic RNA that includes the 3′ end of the genome. The RNA polymerase nsP4 is a read-through protein present early during infection. After replication is established, protein production switches to the structural proteins C, E3, E2, 6K, and E1. The C protein autoproteolytically cleaves itself from the remaining polyprotein. Only E1, E2, and C are found in the mature virion. In some cases, E3 may also be associated with the virus particles Virus DB: VBRC genome browser accession VG0000908.