Prolyl isomerization controls activation kinetics of a cyclic nucleotide-gated ion channel

Abstract

SthK, a cyclic nucleotide-gated ion channel from Spirochaeta thermophila activates slowly upon cAMP increase. Here, authors investigate cAMP-induced activation in purified SthK channels using stopped-flow assays and enzymatic catalysis and reveal that the cis/trans conformation of a conserved proline in the cyclic nucleotide-binding domain determines the activation kinetics of SthK.