Two distinct ferredoxin-NADP(+) -oxidoreductase (FNR) isoforms were found in chloroplasts of Arabidopsis thaliana, FNR-1 (AT5G66190) and FNR-2 (AT1G20020) . The FNR proteins are present in both chloroplast stroma and thylakoid membranes in chloroplasts but are more abundant in the stroma.
