Nucleotide sequence of the 3'-terminal region of artichoke mottle crinckle tombusvirus RNA

The nucleotide sequence of 2200 nucleotides from the 3' end of artichoke mottled crinkle tombusvirus (AMCV) was determined using the dideoxy method on both strands of pUC-cloned cDNA templates. The region examined contains three open reading frames (ORFs) and a 349 nucleotides long 3'-terminal non coding region which shares high degree of homology with that of other tombusviruses. The three ORFs code for proteins with Mr 41,049 (41K), Mr 21,502 (22K) and Mr 19,137 (19K). The corresponding gene positions are: 79-1242 (41K), 1283-1849 (22K) and 1315-1830 (19K). The amino acid sequence of the 41K ORF is constituted by 388 residues, i.e. one residue longer than a previous estimate. This was due to the fact that a proline was missed. On the contrary, this residue was unambiguously identified by us at position 82. By analogy with the other tombusviruses, the 41K is the coat protein whereas 22K and 19K have unknown function and are encoded by two nested ORFs. The amino acid sequence ofAMCV coat protein shares high degree of homology with that of petunia asteroid mosaic (PAMV), cucumber necrosis (CNV) and cymbidium ringspot (CyRSV) tombusviruses. In particular, the R and S domains are highly conserved whereas a different degree of homology (in parentheses) was found between P domain (6) of the following pairs of viruses: AMCV/CNV (22%), AMCV/CyRSV (17%), AMCV/PAMV (83%).