Interactions of plant viral RNAs and tRNA nucleotidyl transferase

Ribonucleic acid from TMV and BMV can accept AMP and CMP when digested with VPD. This incorporation is catalyzed by E. coli and yeast tRNA nucleotidyl transferases. Complex formation is obtained between TYMV RNA and tRNA nucleotidyl transferase in sucrose gradients while TMV and BMV RNAs failed to form a complex in the same conditions. The affinity of the enzyme for viral RNAs is lower than the affinity for tRNA as shown by complex formation on nitrocellulose filters and competition with tRNA. Coat protein from TMV particles enhances AMP and CMP incorporation onto tRNA catalyzed by the E. coli tRNA nucleotidyl transferase.