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 (By similarity). Homomultimer. Associates with itself into higher-order structures, including dimers, trimers and tetramers. Associates with the GP2b-GP3-GP4 complex (By similarity). Myristoylated. Not glycosylated. Belongs to the arteriviridae E protein family.