Complete sequence and genome structure of cactus mild mottle virus.

We have completed the genomic sequence of a tobamovirus, cactus mild mottle virus (CMMoV), and compared it to those of other known tobamoviruses. The complete genome sequence of CMMoV consists of 6,449 nucleotides. The genome RNA of the virus contains four open reading frames, encoding, from the 5' to the 3' end, the 120-kDa viral replicase, the 186-kDa viral polymerase, the 33-kDa movement protein and the 18-kDa coat protein. Overall amino acid similarities for the four viral proteins of CMMoV ranged from 16.3 to 44.4% compared to those of 20 other tobamoviruses. Phylogenetic analysis of the viral replicases and MP revealed that CMMoV is closely related to cucurbit-infecting tobamoviruses, while the CMMoV CP is more closely related to brassica- and solanaceous-infecting tobamoviruses.