NaK - Non-selective Tetrameric Ion Channels

Family:
Non-selective Tetrameric Ion Channels

Topology:
The NaK channel is a homotetramer with each of the four identical subunits containing transmembrane helices (M1 and M2), an interfacial helix (M0), a pore helix (P), and a selectivity filter to conduct ions.

Function:
The NaK channel is prokaryotic non-selective tetrameric ion channel which conducts sodium (Na⁺) and potassium (K⁺) ions. The channel contains a transmembrane aqueous pore that transports ions through facilitated diffusion. It maintains the ionic flux across cell membranes with Na⁺ ions that depolarize the membrane potential and K⁺ ions that repolarize the membrane potential. The NaK channelcontrols biological functions including coordination of contraction and transport of metal ion cofactors of enzymes.