Table 3. Aminoacylation levels of mature valine tRNAs.

tRNA isotype/genes	Percentage of aminoacylated tRNA
	rph-1	rnpA49 rph-1	rnpA49 rph-1/valU+ valW+	rph+
Val1/valU, X,Y, T, Z	39 ± 2	17 ± 6	37 ± 3	41 ± 5
Val2/valV, W	38 ± 4	20 ± 3	37 ± 3	47 ± 5

The percentage of each aminoacylated tRNA was determined by the method of Varshney (27) as previously described (33). valU⁺ and valW⁺ represent tRNA species transcribed from plasmids pAAK11 and pAAK13, respectively as 5′-mature molecules with a leuU transcription terminator known to be removed efficiently by RNase E (15) (See Materials and Methods). Data shown are the average of at least two independent determinations.