transmembrane domains, and contain two nucleotide-binding domains on the cytoplasmic side. These allow for nucleotide-mediated regulation of the potassium channel, and are critical in its roles as a sensor of metabolic status. These SUR subunits are also sensitive to sulfonylureas, MgATP (the magnesium salt of ATP), and some other pharmacological channel openers. While all sarcK_ATP are constructed of eight subunits in this 4:4 ratio, their precise composition varies with tissue type.

MitoK_ATP