Genome sequence of a citrus tristeza virus isolate

The genome of a citrus tristeza virus severe strain from Mexico was completely sequenced. The 19 300 nt genome has 12 open reading frames (ORFs) encoding for 15 proteins and two UTRs (5' and 3' - UTR). The first ORF starts at the nucleotide 108 position and comprises 9587 m, and it encodes for three overlapping proteins, a large polyprotein of 357 kDa that contains two papain-like proteases (P-PRO), a methyltransferase (MT) and a helicase (HEL). The second ORF overlaps on the last 55 nt of the papain-like proteases and encodes for a 47 kDa putative RNA-dependent RNA polymerase (RdRp) with a replication function. The following ORFs encodes for 10 proteins from 6 to 65 kDa. Both genomes had 55 % identity at 5'UTR, 57.9 % at T30, 100 % at SY568, 58.9 % at T36 and VT, and 96 % identity at 3' UTR for all isolates. Average of putative amino acid sequences identities showed of 87.0 % with a mild isolate (T30) and 85.9 %, 93.7 % and 85.13 % with severe isolates T30, SY568, T36 and VT, respectively.