Representative single-channel recordings of WT/E71A heteromers purified by SDS-PAGE. All measurements were done at ±100 mV in 200 mM KCl, buffered with 10 mM HEPES, pH 7.0, in the cis chamber and 200 mM KCl, buffered with 10 mM succinic acid, pH 4.0, in the trans chamber. The traces were digitally filtered at 1 kHz for display. All-points histograms of the traces are shown.