K+ channels are multi-subunit allosteric membrane proteins that transit between closed and open states in response to an external stimulus in a process known as gating. A remarkable feature of K+ channels is that they display a cooperative phenomenon during the gating process. Such switch-like behavior is critical for the physiological functions of K+ channels, which permits a much more sensitive response to a small change in the external stimulus in the cellular context. MthK is a Ca2+-gated K+ channel from Methanobacterium thermoautotrophicum that contains a conserved C-terminal ligand-binding domain termed the RCK domain for its role in regulating the conductance of K+. Previous electrophysiological studies of MthK gating have demonstrated a steep Ca2+ dependence, consistent with a positive inter-subunit cooperativity and strong energetic coupling between Ca2+-binding and channel opening. Here you can see the cryoEM structure of the MthK Calcium-Gated Potassium Channel from Methanothermobacter thermautotrophicus (PDB code: 8DJB)

#molecularart ... #immolecular ... #channel ... #potassium ... #calcium ... #gated ... #complex ... #methanothermobacter ... #cryoem

Structure rendered with @proteinimaging and depicted with @corelphotopaint