. 2011 Nov 21;40(5):2247–2257. doi: 10.1093/nar/gkr1052

Table 3.

TnaC residue changes that affect tnaA’-‘lacZ expression in bacterial cell

TnaC peptide	β-gal activity (Miller units)^a ± SD		Induction ratio (+Trp/−Trp)^b
TnaC peptide	−Trp	+Trp	Induction ratio (+Trp/−Trp)^b
wt	30 ± 1	717 ± 85	23.9
W12R	51 ± 3	42 ± 2	0.8
D16A	30 ± 1	29 ± 0	1.0
K18A	23 ± 1	985 ± 20	42.8

^aCultures of E. coli bacterial strains AW216 (Wt), AW221 (W12R), AW326 (K18A) and AW600 (D16A) were grown in minimal medium plus 0.2% glycerol, 0.05% acid-hydrolyzed casein, 0.01% vitamin B1 and 100 µg/ml ampicillin with (+Trp) or without (−Trp) 100 µg/ml Trp. β-gal assays were performed in three independent experiments.

^bRatio of values for cultures grown with Trp (+Trp) and those grown without Trp (−Trp).