Trna-uke Properties of Tobacco Rattle Virus Rna Nucleic Acids

ABBTRACT Thi 3' terainal forty nucleotides of tobraviral RNAs readily fold into a tertiary structure, reseabling that of tyaoand tobaaoviral RNAs. The latttr RNA* possess a tRNA-like structure at their 3' m d that is recognized by a nUBber of tRNA-specific enzyaes (Rietveld et al. (1984), EHBO J. 2, 26132619). Characteristic for thiir aainoacyl acctptor a m is tht priunct of a •o-calltd pseudoknot which Ht noH also find In a corresponding potition at the 3' terainus of TRV RNA2 (PSB strain). The nucleotida sequences of all tobraviral RNAs analysed so far indicate that thty all possess a slnilar 3' tarainal structura. A doaain rasaabling the anticodon are of canonical tRNA is not raadily recognizable. TRV RNA2 can be adenylated with CTP, ATP|tRNA nucleotidyl transferase and ATP. It is unable, however, to accept any of the twenty concern aaino acids when incubated with ATP and aainoacyl-tRNA synthetases froa wheat gera or yeast. We conclude that TRV RNA contains a tRNA-like structure, which, in contrast to the tyaoand tobaaoviral tRNAlike structures, cannot be aninoacylated. It is unlikely therefore, that aainoacylation of plant viral RNAs with a tRNA-like structure is a prerequisite for viral RNA replication.