GENOMIC SEQUENCE OF PHYSALIS MOTTLE VIRUS AND ITS EVOLUTIONARY RELATIONSHIP WITH OTHER TYMOVIRUSES

The genome of physalis mottle tymovirus (PhMV) is 6673 nucleotides lon g and is rich in cytosine residues (40.58%) like other tymoviruses. Th e organization of the genes is also similar to that of five other tymo viruses whose sequences are known. However, PhMV has the longest 3' no ncoding region as well as the longest replicase (RP:) ORE The RP seque nces are similar to those of other tymoviruses (48-60% identity) where as the coat proteins (CP) and the overlapping proteins (OP) are conser ved to a lesser extent (30-50% and 26-34% respectively). A tetra pepti de ''GILG'' was found to be present in all the tymoviral OPs. The PhMV RP also possesses the methyl transferase, polymerase and the helicase motifs found in all the Sindbis-like super group of plant viruses. A phylogenetic analysis of the six tymoviral sequences revealed that the y do not have a rigid hierarchical similarity relationship.