Nucleotide sequence and genome organization of Cucurbit yellow stunting disorder virus RNA1

The complete nucleotide sequence of Cucurbit yellow stunting disorder virus (CYSDV) RNA1, a member of the Crinivirus genus in the Closteroviridae, was determined. CYSDV RNA1 is 9126 nucleotides long and contains two overlapping open reading frames (ORFs) that encode the replication module, consisting of the putative papain-like cysteine proteinase, methyl transferase, helicase, and polymerase domains, a small 5 kDa hydrophobic protein and two further downstream ORFs potentially encoding proteins respectively 25 and 22 kDa in size. The genomic position and homology of the four domains comprising the replication module appear to be similar for all sequenced criniviruses but there is divergence in the downstream ORFs, in terms of number, size, position and sequence homology.