Mediates the conversion of chorismate to prephenate. chorismate = prephenate No allosteric regulation. Metabolic intermediate biosynthesis; prephenate biosynthesis; prephenate from chorismate: step 1/1. Homodimer. Expressed in root, stem, stigma, anther, leaf, petal tube, petal limb and sepal tissues with highest levels in petal tubes and stems. Expressed at similar levels throughout all flowering stages but accumulates in senescing flowers.