Sequence analysis and product assignment of segment 7 of the rice dwarf virus genome.

The complete nucleotide sequence of segment 7 of the rice dwarf virus (RDV) genome was determined. The segment was 1696 bp long and its plus-strand terminal sequence, 5'GGCAAA---UGAU3', was in agreement with the consensus sequence previously found in other segments of RDV. A 10 bp inverted repeat was found adjacent to the termini. A single long open reading frame extended for 1518 bp from the first AUG triplet (positions 26 to 28), and encoded a polypeptide of 506 amino acids (Mr 55,339). This protein had 32% identity in the amino acid sequence to the 57K protein encoded by segment 7 of the wound tumour virus genome. The translation product of transcript RNA made from 'tailored' cDNA of RDV segment 7 comigrated with the 60K core protein of RDV in 10% polyacrylamide gel and reacted with antiserum against the 60K core protein of RDV. Segment 7 of the RDV genome therefore codes for the 60K core protein.