Pleiotrophic effects of point mutations in yeast tRNAAsp on the base modification pattern

The base-modification pattern has been studied in several synthetic variants of yeast tRNAAsp injected into Xenopus laevis oocytes. Certain point mutations in the D-stem and the varlabie loop of the tRNA led to considerabiy decreased levels of m1G37, ψ40 and Q34/manQ34 in the anticodon stem or loop and an increased rate of synthesis for m5C49 in the T-stem. The formation of m2G6 in the aminoacyl-stem was not atfected in any of the tRNA-variants. Thus, mutations in one part of the tRNA-moiecuie can have long-range effects on the interactions between another part of the IRNA and the tRNA modifying enzymes.