Fig. 2: Tripartite interactions of the Kv4.2 N terminus, Kv4.2 C terminus and KChIP1.
From: Structural basis of gating modulation of Kv4 channel complexes

a, Overall structure of the Kv4.2–KChIP1 complex. The two neighbouring Kv4.2 subunits and one KChIP1 subunit are coloured yellow, red and blue, respectively. The C-terminal cytoplasmic S6 helix stops at S450 when it reaches the bottom of the complex. The interaction site of Kv4.2 and KChIP1 is highlighted by a dotted box. A magnified view from the direction of the arrow is presented in b. b, c, Comparison of the Kv4–KChIP1 complex with (b) or without (c) the Kv4 C terminus. Bottom views of the Kv4.2 (full-length)–KChIP1 complex (b) and the Kv4.3(T1)–KChIP1 complex (c; Protein Data Bank (PDB) code: 2NZ0) are shown. The neighbouring Kv4 subunits are coloured red and yellow. The Kv4.2 S6 helix (Kv4.2-S6) extends downward to the bottom of the complex (S450) and is further followed by the C-terminal segment (Kv4.2-C) consisting of a short helix and a loop (S472–D495), which occupies the hydrophobic space generated by the Kv4.2 N terminus (Kv4.2-N) and KChIP1 (b). d, Inter-subunit interaction of the Kv4.2 N and C termini. Residues involved in the interaction are shown. Two neighbouring Kv4.2 subunits are coloured red and yellow. e, Interaction of the Kv4.2 C terminus (red) and KChIP1 (blue). Residues involved in the interaction are shown. f, The Kv4.2 intracellular S6 helix is captured by KChIP1 and the Kv4.2 C terminus. Residues involved in the interaction are shown.