Fig. 6.

RNA polymerase and DnaC mutations improve the viability of polA priB cells.

A. Synthetic lethality of polA priB cells. Each assay is labelled as described in the legend to Fig. 2C.

B. Relative plating efficiency of polA priB cells on LB and minimal salts agar. The strains indicated were derived using 56/2 minimal salts agar media. Single colonies were grown in liquid 56/2 salts to an A₆₅₀ of 0.4, serially diluted in 10-fold steps from 10⁻¹ to 10⁻⁵ and 10 μl of samples of each dilution were spotted on LB or minimal salts agar as indicated. Plates were photographed after 48 h incubation.

C. Synthetic lethality assays demonstrating robust growth on LB agar of polA priB cells carrying the indicated rpoA alleles or dnaC809,820. Each image is labelled as described in the legend to Fig. 2C.