Forms alternative pathway for phenylalanine biosynthesis. Can catalyze two reactions: prephenate dehydratase and arogenate dehydratase. May have a role in chemotaxis or transport. H(+) + prephenate = 3-phenylpyruvate + CO2 + H2O H(+) + L-arogenate = CO2 + H2O + L-phenylalanine Amino-acid biosynthesis; L-phenylalanine biosynthesis; L-phenylalanine from L-arogenate: step 1/1. Amino-acid biosynthesis; L-phenylalanine biosynthesis; phenylpyruvate from prephenate: step 1/1. Homodimer. Belongs to the bacterial solute-binding protein 3 family.