FIGURE 1.

Sequence alignment of representative K⁺ channels. The sequences represent the small conductance Ca²⁺-activated K⁺ channels (SK3, SK2, and SK1), the intermediate conductance Ca²⁺-activated K⁺ channels (IK), the large conductance Ca²⁺-activated K⁺ channel (BK), the potassium channel from Streptomyces lividans (KcsA), the voltage-gated potassium channel Kv1.2, the inwardly rectifying potassium channel Kir2.2, and the human ERG (hERG) potassium channel. Residues are shaded according to their degree of conservation. Asterisks indicate residues of the SK3 channel that were changed in later functional studies.