Ferredoxins are iron-sulfur proteins that transfer electrons in a wide variety of metabolic reactions. Occupies a key position both for transferring the photoreducing power to Fd-NADP(+) oxidoreductase (FNR), hence the formation of NADPH, and for mediating the cyclic electron flow around photosystem I (PSI). Binds 1 [2Fe-2S] cluster. E(0) is -406 mV. Expressed almost exclusively in bundle-sheath. Belongs to the 2Fe2S plant-type ferredoxin family.