Amino acid sequence of spinach ferredoxin:NADP+ oxidoreductase.

The amino acid sequence of spinach ferredoxin: NADP+ oxidoreductase was determined by using overlapping sets of peptides derived by cleavage at arginyl or methionyl residues. The protein from different preparations varied in its length at the amino terminus. In the longest form the amino terminus is blocked with a pyroglutamyl residue, as determined by NMR. A single disulfide bond was placed between cysteine residues 132 and 137. The 314-residue sequence corresponds to a molecular weight of 35 317. The carboxyl-terminal half of the sequence has been fit to the electron density map of the NADP binding domain, revealing that this portion of the chain forms a typical nucleotide binding fold.