Minor envelope protein. May function as a viroporin in the virion envelope that facilitates uncoating of the virus in order to release the genomic RNA into the cytoplasm for subsequent replication. Homooligomer. Associates with itself into higher-order structures, including dimers, trimers and tetramers. Associates with the GP2a-GP3-GP4 complex (Probable). Myristoylated. Not glycosylated. Belongs to the arteriviridae E protein family.