Fig 5.

Overexpression of citrate synthase in citB mutant strains is not suppressed by a ccpC null mutation. (A) Expression levels of citZ-lacZ in wild-type (KBP44), citB null (KBP45), ccpC null (KBP48), and ccpC citB null (KBP49) cells were determined, and β-galactosidase activity was measured at the indicated time points during growth in DS medium. (B) Levels of CS protein in cell extracts of wild-type (KBP26), citB null (KBP51), ccpC null (KBP52), and ccpC citB null (KBP54) strains were determined. Cell extracts were generated after 3 and 4 h of growth in DS medium. Extracts were analyzed by Western blotting using polyclonal antibodies raised to CS-II and CodY (loading control). The bands were quantitated, and values are presented as a ratio of CS to CodY, normalized to the ratio of the wild-type strain expression level at 3 h. Immunoblotting and quantification of a representative experiment of two are shown.