FIGURE 1.

Model of potassium channel gating. A: The TM6 domain of K_V is relatively linear at rest. Activation involves a swivel and bending motion proximate to a “hinge” region near the middle of TM6. B: In the intact channel, four linear TM6 domains are closely opposed, resulting in a severe narrowing of the pore (i.e., the gate). As pictured, activation induces a bend in each subunit, moving them slightly apart and thereby opening the gate, which allows the passage of potassium ions. Adapted with permission from Sansom MS, Shrivastava IH, Bright JN. Potassium channels: Structures, models, simulations [Review]. Biochim Biophys Acta 2002;1565:294–307.