Fig. 7: Shallow Mn^II pool depleted in un-supplemented medium but steady-state availabilities sustained in high Mn^II, Ni^II and Co^II.

qPCR of a mntS (regulated by Mn^II-MntR), b fepD (Fe^II-Fur), c zntA (Zn^II-ZntR), d copA (Cu^I-CueR), e rcnA (Co^II-RcnR), f rcnA (Ni^II-RcnR), as log₂ change relative to respective lowest measured transcript abundance observed in Foster et al.²⁷ using chelator, metal and/or H₂O₂ supplemented cells ( ~ 0). ∆Cq values in Source Data TXT for Fig. 7, data are mean ± SD of n = 3 independent biological replicates (square, circle, triangle) except where dagger n = 2. MntR and Fur target gene transcripts increase in low Mn^II and Fe^II (MntR and Fur are metal-dependent co-repressors), but other transcripts increase in high availabilities of cognate metals (regulated by activators or metal-dependent de-repressors). Previous log₂(fold change) qPCR at high metal-boundaries (red dashed lines, 0 for Fur) and at low metal boundaries (black dashed lines for MntR and Fur, 0 for others) are shown. Arrows show previous log₂(fold change) qPCR for cognate transcripts isolated from cells grown in LB²⁷. Panels (a) and (b) show expression at 0 h, 1 h, 1.5 h, 18 h after addition of arabinose to un-supplemented medium to induce low expression of MncA at 18 °C. After 18 h MntR regulated mntS transcripts pass the low Mn^II boundary (DNA occupancy θ_D 0.01) (panel a) further quantified in Supplementary Fig. 18. The Mn^II pool is shallow and depleted in LB. For Fur-regulated fepD the log₂ scale reports modest depletion of intracellular available Fe^II at 18 h in un-supplemented medium (Supplementary Fig. 18). The first two columns (panels c–f) show negligible change in availability of Zn^II, Cu^I, Co^II or Ni^II after 18 h MncA expression in non-supplemented medium. Final four columns (panels a, c–f) report log₂(fold change) in metal-supplemented media either with or without expression of MncA as indicated. Steady-state Mn^II availability approximating upper Mn^II boundary sustained to 18 h in 4 mM manganese (panel a). Steady-state approximating the upper metal boundary is also sustained in high Ni^II and Co^II, but not Cu^I and Zn^II (panels c–f). Source data are provided as a Source Data file.