The 3 '-terminal sequence of Chinese yam necrotic mosaic virus genomic RNA: a close relationship with macluravirus

The nucleotide sequence of the 3'-terminal 1,905 residues of the Chinese ya m necrotic mosaic virus (ChYNMV) RNA genome was determined. It contains one long open reading frame, which consists of 1,671 nucleotides encoding a pr otein of 557 amino acid residues. A partial amino acid sequence of the coat protein determined from purified ChYNMV particles was identical to the por tion of the amino acid sequence deduced from the determined nucleotide sequ ence, which suggests that the nucleotide sequence includes the coat protein gene. Surprisingly, a homology search using the deduced amino acids sequen ce of the coat protein revealed that ChYNMV is closely related to the genus Macluravirus within the family Potyviridae, although the virus has long be en considered to be a carlavirus. Identification of cylindrical cytoplasmic inclusions, which are characteristic of the family Potyviridae, in ChYNMV- infected Chinese yam cells, as well as the morphology and length (660 nm) o f the purified virus particles, support including the virus as a tentative new member of the genus Macluravirus.