Currents induced by deoxy-fluoro derivatives of α-phenyl glucoside in oocytes expressing OsSUT1 wild type or OsSUT1(R188K). (A) Xenopus oocytes expressing OsSUT1 wild type were voltage clamped at -40mV in Na ringer solution at pH 5.6. Currents were recorded in response to application of the following substrates at 30 mM: α-phenyl glucoside (phenyl-glu), phenyl-3-deoxy-3-fluoro-α-glucoside (3deoxy-3F), phenyl-4-deoxy-4-fluoro-α-glucoside (4deoxy-4F), and sucrose (suc). Zero current is indicated (−0). (B) Currents recorded in oocytes expressing OsSUT1(R188K) in response to the same substrates and using the same conditions as in A.