TABLE 3.

TRAP-mediated regulation of trpG, trpP, and ycbK expression

Relevant genotype	Fusion	β-Galactosidase activitya			Inhibition (ΔmtrB/WT)b
		−Trp	+Trp	−Trp/+Trp
WT	trpG′-′lacZ	110 ± 20	21 ± 4	5.2	12
ΔmtrB	trpG′-′lacZ	260 ± 35	260 ± 20	1.0
WT	trpP′-′lacZ	200 ± 30	1.3 ± 0.3	150	920
ΔmtrB	trpP′-′lacZ	1,200 ± 160	1,200 ± 220	1.0
WT	ycbK′-′lacZ	12 ± 2	1.3 ± 0.2	9.2	21
ΔmtrB	ycbK′-′lacZ	30 ± 6	27 ± 4	1.1

^aβ-Galactosidase activities are given in Miller units (20). Values are averages for at least three independent experiments ± standard deviations.

^bThe extent of TRAP-dependent inhibition was determined by dividing the value for the mtrB mutant by the value for the corresponding WT strain in the presence of tryptophan.