Residues from the 334–337 region of Kir6.2 are required for wild-type ATP sensitivity. (A) Representative macroscopic current at −80 mV from a patch expressing channels formed from Kir6.2∷4.1[334–337] and SUR1 in response to alternating 0.1 and 5,000 μM ATP. The thin horizontal line indicates zero current. (B) ATP sensitivity of the 334–337 region chimeras: ▴, Kir6.2∷2.1[334–337] channels and ■, Kir6.2∷4.1[334–337] channels, compared with •, wild-type Kir6.2 channels, taken from Fig. 1B.