Figure 7
From: Structural basis for the inhibition of voltage-dependent K+ channel by gating modifier toxin
VSTx1-VSD complex in the physiological environment.
(a) Schematic representation of the DM molecules surrounding the VSTx1-VSD complex, where the acyl chains of the DM molecules interact with the transmembrane region of VSD. The residues of VSTx1 cross-saturated from DM and VSD are colored cyan and magenta, respectively and those with no data are colored black. (b) Comparison of the supposed environments of the VSTx1-VSD complex in DM micelles and phospholipid bilayer. Surface properties of VSTx1 are shown, where the acidic, basic and hydrophobic residues are colored red, blue and green, respectively. (c) VSTx1 binding surface in a tetrameric Kv channel. VSTx1-VSD complex model is superimposed to the crystal structure of Kv1.2–Kv2.1 chimera channel (PDB code 2R9R) (left) and then one VSD molecule of Kv1.2–Kv2.1 chimera channel is substituted by VSTx1-VSD complex model, followed by 70° rotation according to the previous EPR data where the arrangement of VSD and pore domain in KvAP is indicated to be rotated 70° to 100° relative to that of Kv1.2–Kv2.1 chimera39 (right).
