FIG. 2.

Locations of yeast 25S rRNA mutants characterized in the present study. Nucleotide sequence of the distal end of yeast helix 38 (the A-site finger [ASF]) is shown using S. cerevisiae 25S rRNA numbering. Mutagenized bases are blocked in color. The local atomic resolution structure of the E. coli ribosome (39) using PDB files 1PNS and 1PNU were modeled by using PyMOL (6). The aa-tRNA is depicted in orange, and the anticodon (AC) and D-loops (D) are indicated. Small ribosomal protein S15 is the yeast equivalent of E. coli S13. Mutagenized bases in helix 38 are colored.