Box figure.

Ribbon representation of the X-ray structure of a paddle chimera between the Kv2.1 and Kv1.2 channel viewed from the external side of the membrane (top view) and from within the membrane (side view)⁵⁷. The S3b-S4 paddle motif is colored blue, the pore domain (S5-S6) is colored yellow and possible lipid molecules are colored grey. Basic residues in S4 are shown as stick representations (Protein Data Bank accession ID is 2R9R). The side view of the chimeric channel shows the S1–S4 voltage-sensing domain and its interface with the pore domain together with the possible location of lipid molecules.