phoa gene fusions带 Translational protein fusion Alkaline phosphatase is expressed only in periplasm Foreign gene product has to be expressed outside of cytoplasm In vector, signal sequence mutations block export of alkaline phosphatase and render it inactive BIOL 533 Lecture 4BIOL 533 10 Lecture 4 phoA Gene Fusions • Translational protein fusion • Alkaline phosphatase is expressed only in periplasm • Foreign gene product has to be expressed outside of cytoplasm • In vector, signal sequence mutations block export of alkaline phosphatase and render it inactive