Figure 3

Hfq is not implicated in autogeneous repression of the rpsO mRNA by S15. (A) β-Galactosidase activities of the rpsO'-'lacZ chromosomal fusion in the hfq⁺ and hfq Δ derivatives of strain IBrpsO188::lacZ (Materials and methods) carrying plasmids pACYC184 (p) and its derivative pS15 expressing the rpsO gene. (B) Northern-blot analysis of the rpsO mRNA in strain IBrpsO188::lacZ transformed with pACYC184 (p) and its derivatives pS15 and pHfq (pTX381). Lower panel shows the amount of 5S RNA per lane. RNA was extracted from cells grown at 37°C to OD₆₀₀≈0.4 in LB supplemented with chloramphenicol (34 μg/μl).