Supplementary Information

Supplementary Figure 1 - Activity of the yfiD promoter under aerobic and microaerobic growth

The activity of the ArcA-P dependent yfiD promoter was assessed using a yfiD-lacZ reporter fusion on plasmid pGJ66. Cells were grown aerobically (top)or microaerobically bottom) as described in methods. Note the scales differ between aerobic and microaerobic.

Supplementary Figure 2 - Activity of the pfl promoter under anaerobic growth

The activity of the ArcA-P dependent pflB promoter was assessed using a pflB-lacZ reporter fusion. Cells were grown microaerobically (Lane 1) or anaerobically (Lane 2) as described in methods. The pflB promoter activity is increased under anaerobic growth. Wild-type: MG1655.

Supplementary Figure 3 - The menaquinone and ubiquinone biosynthetic pathway

Both, menaquinones (DMK8 and MK8) and ubiquinones (UQ8-H2 and UQ8) are derived from the same precursors, chorismate and octaprenyl diphosphate. The reactions catalysed by MenA and UbiG are shown. Deletion of MenA and UbiG results in the loss of menaquinones and ubiquinones, respectively.

Supplementary Figure 4 - Ubiquinones play a central role as electron carrier in the electron transport chain under aerobic and also microaerobic growth

Shown are the UQ8 reducing dehydrogenases NDH-I, NDH-II as well as the UQ8-H2 oxidising quinol oxidases Cyt bd-I and Cyt bo.

Supplementary Figure 5 - Standard curve used to calculate the amount of ubiquinone

Defined concentrations of UQ10 were used as reference points to calculate the amount of ubiquinone. 1 area unit [AU] of the peak at 290 nm corresponds to 0.012 nmol UQ10.

Supplementary Figure 6 - HPLC traces of the quinone measurements

Shown are the HPLC chromatograms obtained from the quinone measurements. Ubiquinones were detected at 290nm. UQ8-H2 was eluted after 7-8 minutes and UQ8 after 12-13 minutes. Menaquinones were detected at 248nm. DMK8 was eluted after 18-19 minutes and MK8 after 21-22 minutes. Peaks corresponding to UQ8, UQ8-H2, DMK8 and MK8 are labelled.

Supplementary Figure 1

Supplementary Figure 2

Supplementary Figure 3

Supplementary Figure 4

Supplementary Figure 5

Supplementary Figure 6

MG1655 strains

UQs aerobic

MKs aerobic

UQs and MKs microaerobic

BT strains

UQs aerobic

MKs aerobic

UQs and MKs microaerobic

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