Ferredoxin:NADP+ reductase is representative of a large family of flav
oenzymes which catalyze the interchange of reducing equivalents betwee
n one-electron carriers and the two-electron-carrying nicotinamide din
ucleotides. The structure of the enzyme from spinach is known at 1.7 a
ngstrom resolution and this structure, together with results of chemic
al modification and site-directed mutagenesis studies, gives insights
into features of the structure that are important for function.