A different mechanism of C-type inactivation in the Kv-like KcsA mutant E71V

Abstract

C-type inactivation is of great physiological importance particularly in voltage-activated K+ channels (Kv), affecting the firing patterns of neurons and shaping cardiac action potentials. While understanding the molecular basis of inactivation has a direct impact on human health, its structural basis remains unresolved. Knowledge about C-type inactivation has been largely deduced from the pH-activated bacterial K+ channel KcsA, whose selectivity filter under inactivating conditions adopts a constricted conformation at the level of the central glycine (TTVGYGD) that is stabilized by tightly bound water molecules.