Inverted allosteric coupling between activation and inactivation gates in K⁺ channels.

ABSTRACT: The selectivity filter and the activation gate in potassium channels are functionally and structurally coupled. An allosteric coupling underlies C-type inactivation coupled to activation gating in this ion-channel family (i.e., opening of the activation gate triggers the collapse of the channel's selectivity filter). We have identified the second Threonine residue within the TTVGYGD signature sequence of K⁺ channels as a crucial residue for this allosteric communication. A Threonine to Alanine substitution at this position was studied in three representative members of the K⁺-channel family. Interestingly, all of the mutant channels exhibited lack of C-type inactivation gating and an inversion of their allosteric coupling (i.e., closing of the activation gate collapse

SUBMITTER: Labro AJ 

PROVIDER: S-EPMC6003467 | biostudies-literature | 2018 May

REPOSITORIES: biostudies-literature