TABLE 3.

Stp1 regulates GBS hemolytic activity independent of cylE transcription

	β-H/C activity
	Hemolytic titera	Change in hemolytic titer	Change in cylE transcriptionb
		-fold	-fold
A909 (WT)	4	NAc	1
ΔcylE	<1	>0.25	NA
Δstp1	<1	>0.25	0.92 ± 0.1
ΔcovR	128	32	11 ± 0.2
ΔcovRΔstp1	32	8	11 ± 0.13

^a Hemolytic titers were estimated as described (39, 59). The experiment was performed in triplicate, and changes that are >2-fold compared with WT GBS A909 are considered significant.

^b qRT-PCR was performed as described under “Experimental Procedures.” Gene expression is denoted as -fold difference relative to the WT GBS strain A909. S.E. is indicated.

^c NA, not applicable.