FIG. 8.

Loss of CAO activity in atx1Δ cells is restored by exogenous copper or a plasmid-borne copy of the WT atx1⁺ gene. An integrative plasmid expressing a functional GFP-tagged cao1⁺ allele was transformed into cao1Δ and cao1Δ atx1Δ cells. Disruption of the atx1⁺ gene decreased CAO activity levels. The CAO activity defect was corrected either by returning a WT copy of the atx1⁺ gene expressed from a plasmid or by adding CuSO₄ (10 μM) to the growth medium. Roman numerals (I and II) indicate two separate cao1Δ atx1Δ strains in which cao1⁺-GFP was returned by integration.