10         20         30         40         50         60
         |          |          |          |          |          |
MNRGFFNMLG RRPFPAPTAM WRPRRRRQAA PMPARNGLAS QIQQLTTAVS ALVIGQATRP - 60
QNPRPRPPPR QKKQAPKQPP KPKKPKPQEK KKKQPAKTKP GKRQRMALKL EADRLFDVKN - 120
EDGDVIGHAL AMEGKVMKPL HVKGTIDHPV LSKLKFTKSS AYDMEFAQLP VNMRSEAFTY - 180
TSEHPEGFYN WHHGAVQYSG GRFTIPRGVG GRGDSGRPIM DNSGRVVAIV LGGADEGTRT - 240
ALSVVTWNSK GKTIKTTPEG TEEW

Capsid protein possesses a protease activity that results in its autocatalytic cleavage from the nascent structural protein. Following its self-cleavage, the capsid protein transiently associates with ribosomes, and within several minutes the protein binds to viral RNA and rapidly assembles into icosaedric core particles. The resulting nucleocapsid eventually associates with the cytoplasmic domain of E2 at the cell membrane, leading to budding and formation of mature virions. New virions attach to target cells, and after endocytosis their membrane fuses with the target cell membrane. This leads to the release of the nucleocapsid into the cytoplasm, followed by an uncoating event necessary for the genomic RNA to become accessible. The uncoating might be triggered by the interaction of capsid proteins with ribosomes. Binding of ribosomes would release the genomic RNA since the same region is genomic RNA-binding and ribosome-binding. Capsid protein is Cleavage product 1 of Structural polyprotein, comprised of aa 1-264 of the polyprotein.