Acetolactate synthase, large subunit, biosynthetic (IPR012846)

Short name: Acetolactate_synth_lsu

Overlapping homologous superfamilies

Family relationships



Two groups of proteins form acetolactate from two molecules of pyruvate. The type of acetolactate synthase described in this entry also catalyzes the formation of acetohydroxybutyrate from pyruvate and 2-oxobutyrate, an early step in the branched chain amino acid biosynthesis; it is therefore also termed acetohydroxyacid synthase. In bacteria, this catalytic chain is associated with a smaller regulatory chain in an alpha2/beta2 heterotetramer. Acetolactate synthase is a thiamine pyrophosphate enzyme. In this type, FAD and Mg++ are also found. Several isozymes of this enzyme are found in Escherichia coli (strain K12), one of which contains a frameshift in the large subunit gene and is not expressed.

GO terms

Biological Process

GO:0009082 branched-chain amino acid biosynthetic process

Molecular Function

GO:0003984 acetolactate synthase activity
GO:0050660 flavin adenine dinucleotide binding
GO:0000287 magnesium ion binding
GO:0030976 thiamine pyrophosphate binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.