FIG 4.
Quantification of cellular UQ8 contents of Δubi E. coli mutant strains expressing the UbiFn proteins. The Δubi E. coli mutant strains transformed with pTrc99a (vec) or pTrc99a encompassing the ubiFn genes were grown overnight at 37°C in LB medium (A) or M9 minimal medium (B) with 0.4% (wt/vol) glucose as the sole carbon source. Expression of the UbiFn proteins is described in the legend of Fig. 3. Quantifications are expressed as percentages of the control value, which corresponds to the UQ8 content of the wild-type strain (n = 3). ****, P < 0.0001; **, P < 0.005 (by unpaired Student’s t test).