Effect of a native chromosomal tRNA gene on PTR3 expression. (A) Cartoon of the tY(GUA)F2 locus on chromosome VI. Open arrowheads indicate the transcriptional orientation, and the distance between the tRNA gene and the flanking non-Ty ORFs is given in base pairs. (B) RNA blot analysis of cells containing various chromosomal alleles of the tY(GUA)F2 tRNA gene. The level ofPTR3 to ACT1 RNA was determined for each sample. (C) PTR3 levels in the presence of no tRNA gene, an actively transcribed tRNA gene and a transcriptionally inactive tRNA gene are relative to those in the presence of the wild-type tRNA gene,URA3MX4, sup2+b andsup2+b* relative to wt. (* indicates the presence of the G56 mutation in sup2+b).
