InterPro domain: IPR027271

This superfamily represent the C-terminal domain of the small subunit of acetolactate synthase and the C-terminal domain of the NikR, which is a transcription factor that regulates nickel uptake.

NikR consists of two dimeric DNA binding domains separated by a tetrameric regulatory domain that binds nickel. This protein corresponds to the C-terminal regulatory domain which contains four nickel binding sites at the tetramer interface [ 1 ].

Acetolactate synthase is a tetrameric enzyme, composed of two large and two small subunits, which catalyses the first step in branched-chain amino acid biosynthesis. This reaction is sensitive to certain herbicides [ 2 ].

1. Crystal structure of the nickel-responsive transcription factor NikR. Nat. Struct. Biol. 10, 794-9
2. Identification of an acetolactate synthase small subunit gene in two eukaryotes. Gene 190, 245-9