TABLE 2.

RpoS activity modulated by RssB

Straina	Genotype	β-Galactosidase (U)b
DDS1342	clpP::Cat	24
DDS1343	clpX::Kan	27
DDS1346	rssB::Tet	35
YN236	clpP::Cat rssB::Ttet	39
YN238	clpP::Cat rssB::Tet rpoS::Kan	1.7
YN218	clpP::Cat/prssB+	7.9
YN216	clpX::Kan/prssB+	7.5

^aStrains all carry the dsrB::lacZ fusion and are derived from DDS1340 (32). 

^bCells were grown in M63 medium with 0.2% glucose and vitamin B₁ at 32°C to an OD₆₀₀ of approximately 0.45 and assayed for β-galactosidase as described in Materials and Methods. The values (see Materials and Methods for units) remained relatively constant during exponential growth in these strains. In duplicate experiments, the relative values were reproducible. In experiments done under somewhat different growth conditions, wild-type strains have about one-half to one-third the activity of the clpP or clpX mutant host for the dsrB-lacZ fusion.