Figure 1.

A, HPLC ECD analyses of lipid extracts from 1 mg of E. coli WT or ΔubiK cells transformed with either the empty pK vector (vec) or the pK vector carrying the ubiK gene grown in LB medium in aerobic conditions. The chromatograms are representative of three independent experiments. The peaks corresponding to UQ₈, DMK₈, OPP, and the coenzyme Q₁₀ (UQ₁₀) standard are indicated. B, quantification of cellular UQ₈ content of the E. coli strains described in A based on ECD signal (peak area). C and D, quantification of cellular DMK₈ and MK₈ from chromatograms at 247 nm (see supplemental Fig. S1B). E, quantification (peak area) of OPP from chromatograms at 275 nm (see supplemental Fig. S1D). B–E, mean ± S.E.; n = 3–5; ***, p < 0.001; ****, p < 0.0001, one-way analysis of variance. F, ECD quantification of cellular UQ₈ content of the E. coli WT and ΔubiK cells grown in anaerobic conditions in LB medium; n = 3. G, immunodetection of SPA-tagged proteins UbiE, UbiK, and UbiJ after growth in LB medium under aerobic (+O₂) or anaerobic (−O₂) conditions. Equal loading was verified with immunodetection of the protein LamB and staining of the SDS-PAGE with Coomassie Blue dye. Mw, molecular mass.