Phylogenetic Tree Analysis of UTR and Transmembrane Structure Prediction of Proteins of Genus Bymovirus

Homology and phylogenetic tree analysis of genus Bymovirus suggested that the 5 一UTR of RNA1 and RNA2 of the same virus were more similar than those of the same RNAs of different virus— es．but the instance of 3 UTR was opposite．Secondary structure analysis on polypoteins showed that P3 and 14K encoded by RNA1 contained transmembrane(TM)stuctures．TM region in P3 protein of BaM MV ALS1 isolates was toxic to the E ．coli．By analogy to other members of family Potyviridae． these structures were predicted to have the function as attachment to the membranes．P2 protein en— coded by RNA2 also contained two TM regions．Some BaMMV isolates which were maintained me— chanically for a long period of times occurred deletions in these regions and were not transmitted by Polymyxa graminis．It was suggested that the TM structures were closely related to vector transmis— sion．