Replicates genomic RNA, and might as well transcribe a subgenomic RNA coding for coat protein. Coat protein: encapsidates the viral genome. Forms particles of very flexuous filaments, 619 nm long and 12 nm in width, with obvious cross-banding, helical symmetry and a pitch of c. 3.8 nm. Synthesis remains unclear: either by cleavage of the ORF1 polyprotein, or by translation of a subgenomic RNA. a ribonucleoside 5'-triphosphate + RNA(n) = diphosphate + RNA(n+1) ATP + H2O = ADP + H(+) + phosphate The V-region of the ORF1-encoded protein between the polymerase and the CP, that encodes ORF2 in another frame does not have any functional motifs found in other known plant virus genomes. This region shows high variability among isolates and sequence variants. The N-terminus of the coat protein is blocked.