Figure 5: Mechanism of MloK1 gating with cAMP.
From: Ligand-induced structural changes in the cyclic nucleotide-modulated potassium channel MloK1
(a) The modelled individual subunits of MloK1 in the cAMP-bound (blue) and cAMP-free (yellow) structures are shown, aligned to the selectivity filters. (b) Proposed mechanism based on the alignment shown in a. Left: without cAMP, right: with bound cAMP (symbolized by the yellow jigsaw puzzle piece). cAMP binding leads to CNBDs (purple cylinder) to move 3 Å towards the membrane, while VSDs (green cylinder) move towards the CNBDs and tilt in lipid bilayer. In parallel, the S5-P-S6 core (blue cylinder) twists slightly in a counter-clockwise (CCW) direction when seen from the extracellular side. This is reversed when cAMP dissociates (left). C/O indicate the closed/open channel configurations.
