NUCLEOTIDE-SEQUENCE OF CARNATION RINGSPOT DIANTHOVIRUS RNA-2

RNA-2 of carnation ringspot virus (CRSV), the type member of the dianthovirus group, has been cDNA cloned and sequenced. CRSV RNA-2 is 1394 nucleotides in length and contains a single open reading frame encoding a 304 amino acid polypeptide of 33-8K. Amino acid sequence alignment of this polypeptide with the cell-to-cell movement proteins encoded by RNA-2 of red clover necrotic mosaic virus (RCNMV) Australian (Aus) and Czechoslovakian (TpM-34) isolates indicates 59.6 % and 55.7 % sequence identity, respectively. The N-terminal 230 amino acids are more highly conserved, with 64.3 % and 62.6 % sequence identity, respectively. The cell-to-cell movement proteins of the two RCNMV isolates are themselves 82.5 % and 91.7 % identical when the amino-terminal 230 amino acids are compared. Structural prediction comparison of the RCNMV-Aus, RCNMV-TpM-34 and tobacco mosaic virus cell-to-cell movement proteins to the putative CRSV RNA-2-encoded movement protein suggests that even though no primary amino acid sequence similarity exists, the movement protein polypeptides are possibly similar in structure an function.