SEQUENCE OF RICE HOJA BLANCA TENUIVIRUS RNA-2

The sequence of rice hoja blanca tenuivirus RNA-2 is analysed and comp ared to its counterpart in rice stripe tenuivirus. The RNA encodes two proteins, in an ambisense arrangement. The 94 kD pc2, located in the complementary sense RNA, has several features typical of viral membran e (glyco)proteins, and also has regions of local homology to the glyco proteins of the Phleboviruses (Bunyaviridae). The 23 kD pv2 lies in th e viral sense RNA and has two small conserved domains that are almost exclusively found in retro-viral membrane glycoproteins. Its genome lo cation is analogous to the NSm protein of several of the Bunyaviridae species, which is thought to have a membrane-related function. The two open reading frames are separated by a large intergenic region which, in common with the other tenuivirus ambisense RNA segments, has a sho rt region that is highly conserved between RStV and RHBV. The signific ance of these results with respect to the virus structure and gene exp ression is discussed.