Similarity in structure and function of the 3′-terminal region of the four brome mosaic viral RNAs

A 3′-terminal fragment, about 160 nucleotides long, was cleaved by limited nuclease digestion from each of the four RNA components of brome mosaic virus, and purified by two cycles of gel electrophoresis. These fragments accepted tyrosine in reactions catalyzed by wheat germ aminoacyl-tRNA synthetase. Analyses of nuclease digests suggested that the sequences of the fragments from brome mosaic virus RNA 3 and 4 were identical and that the fragments from RNA 1 and 2 differed from that of RNA 4 only in the positions of two and one nucleotides, respectively. A fragment isolated in a similar way from cowpea chlorotic mottle virus was similar in size to the brome mosaic virus RNA fragments, accepted tyrosine in the presence of wheat germ aminoacyl-tRNA synthetase, but had a substantially different nucleotide sequence.