Acetohydroxy acid Synthase (AKA acetolactate synthase) is a
key enzyme that catalyses the first common step in the biosynthesis
of the essential branched-chain amino acids isoleucine, leucine,
The gm-hra gene has been modified by site directed
mutagenesis (P183A and W560L) from the native soybean als
gene and encodes a version of the enzyme that is tolerant to
als inhibitors such as sulfonylurea herbicide.
It also contains 15 additional nucleotides from the native als gene