Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) FAD/NADH binding domain. (Na+-NQR) provides a means of storing redox reaction energy via the transmembrane translocation of Na2+ ions. The C-terminal domain resembles ferredoxin:NADP+ oxidoreductase, and has NADH and FAD binding sites. (Na+-NQR) is distinct from H+-translocating NADH:quinone oxidoreductases and noncoupled NADH:quinone oxidoreductases. The NAD(P) binding domain of ferredoxin reductase-like proteins catalyze electron transfer between an NAD(P)-binding domain of the alpha/beta class and a discrete (usually N-terminal) domain which vary in orientation with respect to the NAD(P) binding domain. The N-terminal domain of this group typically contains an iron-sulfur cluster binding domain.