TABLE 7.

Comparison of cat and lacZ gene activities

Resident plasmid	par proteins supplied	Relative cat activitya		Induced relative β-galactosidase activityb
		Strain CC4250	Strain CC4253	Strain CC4250	Strain CC4253
pGB2 vector	None	1	1	1	1
pALA2319	ParB	0.55	0.16	0.65	0.02
pALA2306	ParA ParB	0.39	0.16	0.62	0.07
pALA2308	ParAM314I ParB	0.18	0.10	0.04	0.01

^aStrain CC4250 is a derivative of the transcription block strain CC4248 that has a cat gene inserted downstream of lacZ (Fig. 1). Strain CC4253 is a rec⁺ variant of the regional silencing strain of Rodionov et al. (24), BR6903. All values were normalized to the value obtained with the relevant strain (CC4250 or CC4253) when the pGB2 vector was present. Values are averages of three experiments. The cat assays were carried out as described in Materials and Methods. No IPTG was added so that the lacZ gene of strain CC4250 was uninduced.

^bThe β-galactosidase values for CC4250 pGB2 and CC4253 pGB2 were 247 and 386 Miller units, respectively.