InterPro: IPR017719 Indolepyruvate ferredoxin oxidoreductase, beta subunit

This entry represents the beta subunit of indolepyruvate ferredoxin oxidoreductase (IOR; EC:1.2.7.8), an alpha(2)/beta(2) tetramer whose cofactors include TPP, 4Fe4S, and 3Fe-4S. This enzyme is related to several other ketoacid oxidoreductases, including: the ketoacid oxidoreductases for pyruvate (EC:1.2.7.1, POR), 2-ketoglutarate (EC:1.2.7.3, KOR), and 2-oxoisovalerate (EC:1.2.7.7, VOR). These multi-subunit enzymes typically are found in anaerobes and are inactivated by oxygen, such as Pyrococcus furiosus and Methanobacterium thermoautotrophicum, and are inactivated by oxygen. IOR in Pyrococcus acts in the fermentation of all three aromatic amino acids, following removal of the amino group by transamination [1]. In Methanococcus maripaludis, by contrast, IOR acts in the opposite direction, in pathways of amino acid biosynthesis from phenylacetate, indoleacetate, and p-hydroxyphenylacetate [2]. In M. maripaludis and many other species, iorA and iorB are found next to an apparent phenylacetate-CoA ligase.