Pairs of these monomers dimerize and create the interface shown Figure . The entry point of the tunnel contains the herbicide binding site and allows transport of pyruvate molecules to the catalytic region; Glycine 511 is the first used in biosynthesis. This short tunnel can be used as a blockage point for the acetolactate production, and this is the high-binding region of AHAS to which these mentioned herbicides attach via intermolecular attraction. The location from left to right of the green residues is the same as listed.