Purified, recombinant FdC1 contains a [2Fe-2S] cluster. A, native PAGE gel showing the separation of recombinant purified Arabidopsis Fd2, Fd3, and FdC1 proteins. Lanes contain 20 μg of purified protein. B, absorbance spectra of 90 μm purified recombinant Arabidopsis Fd2 (black line) and FdC1 (gray line) based on a ferredoxin ϵ420 of 10 mm−1 cm−1.