FIG. 4.

Effect of depletion of ClpXP protease on the expression of the hilC and hilD genes in the absence of hilC or hilD gene. (A) The expression levels of lacZ fusions to hilC and hilD promoters were assayed. The values represent the means and standard derivations for samples tested at least in triplicate. Plasmid pTKY559 (hilC promoter-lacZ fusion) or pTKY562 (hilD promoter-lacZ fusion) was introduced into bacterial strains χ3306 (clpPX⁺ hilC⁺ hilD⁺), CS2007 (ΔclpPX hilC⁺ hilD⁺), CS2724 (clpPX⁺ ΔhilC hilD⁺), CS3322 (ΔclpPX ΔhilC hilD⁺), CS2725 (clpPX⁺ hilC⁺ ΔhilD), and CS3325 (ΔclpPX hilC⁺ ΔhilD). The resultant strains were used for determination of β-galactosidase activity. (B) Immunoblotting of the cellular lysates using anti-HilC and anti-HilD sera. The strains used were χ3306, CS2007, CS2724, CS3322, CS2725, and CS3325.