Cymbidium mosaic potexvirus RNA: complete nucleotide sequence and phylogenetic analysis

Summary

The complete nucleotide sequence of the genomic RNA of cymbidium mosaic potexvirus (CymMV) was determined to be 6 227 nucleotides in length, excluding the poly (A) tail at the 3′ terminus. Similar to other potexviruses, its genome organisation is comprised of five major open reading frames (ORFs 1 to 5), encoding a M_r 160 KDa putative RNA-dependent RNA polymerase (RdRp); a M_r26KDa/13KDa/10KDa triple-gene-block (TGB) and a M_r 24 KDa coat protein. The CymMV encoded proteins shared a high degree of homology to their corresponding proteins of other members of the potexvirus group. The nucleotide sequence of the 5′ noncoding region (NCR) of CymMV and all other potexviruses initiates with GAAAA. CymMV possesses the shortest 5′ NCR among all potexviruses. Based on phylogenetic comparisons of RdRp and coat protein, CymMV shares a close relationship to PAMV, NMV, WClMV and SMYEaV. This is believed to be the first record of the complete nucleotide sequence of CymMV.