FIGURE 5.

Nutritional and genetic depletion of pABA eliminate the formation of prenyl-pABA. BY4741 wild-type yeast and BY4741Δabz1 yeast mutants were grown overnight in YPD, and then diluted 1:100 (v/v) into fresh Dogal media minus pABA and folate and incubated for 1 day. The day 1 culture was used to inoculate fresh Dogal media (minus pABA and folate), and the process was repeated to generate the day2 and day 3 cultures. The serial dilution into pABA minus media exhausts endogenous stores of pABA (16). Cells were harvested, and lipid extracts were examined for content of Q₆ (filled squares; left y axis), DMQ₆ (open squares; right y axis), and prenyl-pABA (triangles; right y axis).