The genome organization of Beet necrotic yellow vein virus. The filled circles indicate the cap structures, the boxes indicate ORFs, and the black rectangles indicate conserved common sequences preceding the 3'-poly(A) tail. The triangle indicates the location of the predicted protease cleavage site and the asterisk indicates a readthrough amber termination codon. The coat protein (CP), the readthrough protein (RT) and the triple gene block (TGB) are shown by arrows. The methyltransferase domain (MTR), the NTP-binding/helicase domains (HEL), the papain-like proteinase domain (PRO), the GDD replicase domain (POL), the cysteine-rich protein (CYS), and regions involved in virus assembly (ASS), transmission (TRA), symptom expression (SYM) and necrosis (N) are indicated.