Figure 6

The extracellular view at the inner-helices bundle in the open Kv1.3. Bonds C^α-C^β in correolide-sensing residues [15] are shown as either cyan sticks that face the pore or gray sticks directed away from the pore. Red sticks show bonds C^α-C^β in Ile⁴²⁰, the residue whose mutation to Ala results in low expression of Kv1.3 [15]. Four correolide sensing residues face the pore, while Ile⁴²⁰ could stabilize the channel conformation by interacting with the outer helices, which are not shown.