In enzymology, 3-methyl-2-oxobutanoate dehydrogenase (ferredoxin) () is an enzyme that catalyzes the chemical reaction
The substrates of this enzyme are ñ-ketoisovaleric acid, coenzyme A, and oxidized ferredoxin. Its products are isobutyryl-CoA, carbon dioxide, reduced ferredoxin, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with an iron-sulfur protein as acceptor. The systematic name of this enzyme class is . Other names in common use include 2-ketoisovalerate ferredoxin reductase, 3-methyl-2-oxobutanoate synthase (ferredoxin), VOR, branched-chain ketoacid ferredoxin reductase, branched-chain oxo acid ferredoxin reductase, keto-valine-ferredoxin oxidoreductase, ketoisovalerate ferredoxin reductase, and 2-oxoisovalerate ferredoxin reductase.