Aminoacylation of RNA from Several Viruses: Amino Acid Specificity and Differential Activity of Plant, Yeast and Bacterial Synthetases

The RNA of broad bean mottle virus (BBMV), cowpea chlorotic mottle virus (CCMV), and cucumber mosaic virus (CMV) bound tyrosine, as does brome mosaic virus (BMV) RNA. Other amino acids were not bound. Comparison of the efficiency of synthetase enzymes from Escherichia coli, bean, wheat, and Saccharomyces cerevisiae in aminoacylation of RNA from these viruses, and from tobacco mosaic virus (TMV) and turnip yellow mosaic virus (TYMV), showed that the plant enzymes were effective in tyrosylation of RNA from bromoviruses and CMV, whereas the yeast and bacterial enzymes were ineffective. The E. coli enzyme did not esterify TMV RNA with histidine, and the bean enzyme was poor in this ability. All enzymes were able to catalyse valine binding to TYMV RNA. However, 40 mm-KCl inhibited valine binding to TYMV RNA by the bacterial enzyme while its ability to catalyse binding by tRNA was not affected.