FIG. 5.

Mutant tmRNAs have tagging function. (A) Diagram of the three ACA sites introduced into E. coli K-12 tmRNA (adapted from reference 57 with permission of the publisher). Two ACA mutations were introduced into single-strand regions, while the third was introduced into a double-strand region. (B) Radiolabeled lambda repressor is tagged by genomic tmRNA (G), wild-type (wt) tmRNA plasmid (P), each of the single tmRNA mutant plasmids (lanes 1, 2, and 3), and the tmRNA triple mutant plasmid (lane 4). The lambda repressor is not tagged (and hence smaller) in cells lacking tmRNA (−).