[Directed fragmentation of tobacco mosaic virus RNA: excision of 3' terminal sections, containing coat protein genes of tobacco mosaic virus].

The present work demonstrated that RNA of different Tobacco mosaic virus strains (common; A14; Ni118, U2; wheat strain) are selectively cleaved by RNase H from E. coli in the presence of oligodeoxyribonucleotide d(TTTTTTTCCGG) complementary to the stretch of TMV RNA from the 842-nd to the 852-nd nucleotide from 3'-end, e. g. corresponding to the region adjacent to the 3'-terminus of origin of assemble of TMV. Such cleavage yields two main products. One of them--the short S-fragment--is the 3'-terminal part of TMV RNA. This conclusion is based on its ability to accept histidine and its molecular weight is about 0.28 X 10(6). The other main product of TMV RNA cleavage by RNase H is the L-fragment. L-fragment is the 5'-terminal moiety of TMV RNA, as follows from its ability to direct the in vitro synthesis of p110-130, which is known to be encoded in the 5'-terminal TMV RNA region.