THE COMPLETE NUCLEOTIDE-SEQUENCE OF APPLE MOSAIC-VIRUS RNA-3

The complete nucleotide sequence of apple mosaic ilarvirus (ApMV) RNA- 3 has been determined from cloned viral cDNAs. The 5' terminus of RNA- 3 was determined by direct RNA sequencing, while the 3' end was determ ined by polyadenylation of genomic RNA and-sub-cloning using oligo dT. ApMV RNA-3 is 2056 bases in length and encodes at least two open read ing frames. It is similar in size and genome organization to the RNA-3 of other members of the Bromoviridae, which includes ilarviruses. The CP gene is in the 3' half of the molecule, and another large open rea ding frame is upstream of the CP gene and can potentially encode a pro tein of 32 400 daltons. This peptide is the same size and shows limite d sequence homology to an open reading frame located at the 5' ehd of RNA 3 in tobacco streak and prune dwarf ilarviruses and alfalfa mosaic virus, which is postulated to be the viral movement protein. The nucl eic acid sequence was not homologous to tobacco streak virus, prune dw arf virus, alfalfa mosaic virus or other members of the Bromoviridae. The 5'-non-coding region of ApMV RNA-3 contains a 15 base palindromic sequence which encloses a sequence resembling the ICR-2 regions of euk aryotic tRNA gene promoters.