TABLE 4.

Generation of reporter fusions by Red recombination in E. coli, S. enterica, and S. flexneri

Activity measured and species	Fusion	Mean ± SD ina:
		Low-Mg2+ medium	High-Mg2+ medium
Luciferase (relative light units)
S. enterica	gyrA::luc	1,314 ± 42	1,276 ± 62
S. enterica	mgtA::luc	8,830 ± 70	50 ± 9
E. coli	mgtA::luc	6,821 ± 705	30 ± 5
S. flexneri	mgtA::luc	1,078 ± 59	0 ± 0
β-Galactosidase (Miller units)
S. enterica	mgtA::lacZ	112.4 ± 24.0	2.1 ± 0.0
E. coli	mgtA::lacZ	82.7 ± 4.0	5.5 ± 0.5

^aStrains were grown in N-minimal media containing 30 μM MgCl₂ (low-Mg²⁺ medium) or 10 mM MgCl₂ (high-Mg²⁺ medium).