MOLECULAR-CLONING AND NUCLEOTIDE SEQUENCING OF THE 3'-TERMINAL REGIONOF A SOUTH-AFRICAN ISOLATE OF RYEGRASS MOSAIC-VIRUS RNA AND IN-VITRO EXPRESSION OF THE COAT PROTEIN GENE

The 2094 nucleotides at the 3'-terminus of a South African isolate of ryegrass mosaic virus (RGMV) was cloned and sequenced. Two putative po lyprotein cleavage sites were found: Q/L and E/A, both of which are no vel in the Potyviridae. The RGMV-SA cDNA was cloned into an expression vector, pUEX, and a fusion protein of 185 kDa was obtained which reac ted strongly to anti-RGMV-SA antiserum. Alignment of the predicted ami no acid sequence of RGMV-SA with those of other Potyviridae members sh owed limited identity, indicating that RGMV-SA is a definite and disti nct virus.