Figure 4

Loss of selectivity upon mutation of G132A located in the suspected selectivity filter. All recordings were done by applying the voltage-step protocol depicted in Fig. 2E. Representative current traces obtained from TbIRK-expressing oocytes in sodium medium (NaME), potassium medium (KME) and potassium medium supplemented with 10 mM CsCl are shown in the upper row. Recordings obtained with a oocyte expressing the G132A-mutant are shown in the lower row.