FIG 4.

UbiU and UbiV are necessary for the anaerobic conversion of DMQ₈ into UQ₈. (A) Conversion of DMQ₈ to UQ₈ with enzymes of the O₂-dependent and the O₂-independent pathways, indicated above and below arrows (numbering of carbon atoms shown on DMQ₈ and polyprenyl tail represented by R). (B) Quantification by HPLC-MS (monitoring of Na⁺ adducts) of unlabeled (¹²C) and labeled (¹³C₆) DMQ₈ and UQ₈ in ΔubiC ΔubiF cells after aerobic growth and transition to anaerobiosis. (C and D) Same as panel B but with ΔubiC ΔubiF ΔubiU cells (C) and ΔubiC ΔubiF ΔubiV cells (D). nd, not detected. Results are representative of two independent experiments (B to D).