E(rns), E1 and E2 are responsible of cell attachment and subsequent fusion of viral and cellular membrane.
P7 forms a leader sequence to properly orient NS2 in the membrane.
Uncleaved NS2-3 is required for production of infectious virus.
NS2 protease seems to play a vital role in viral RNA replication control and in the pathogenicity of the virus.
NS3 displays three enzymatic activities: serine protease, NTPase and RNA helicase.
NS4A is a cofactor for the NS3 protease activity.
RNA-directed RNA polymerase NS5 replicates the viral (+) and (-) genome.