Cookies on this website
We use cookies to ensure that we give you the best experience on our website. If you click 'Continue' we'll assume that you are happy to receive all cookies and you won't see this message again. Click 'Find out more' for information on how to change your cookie settings.

The structural and functional conversion of the nonselective NaK channel to a K+ selective channel (NaK2K) allows us to identify two key residues, Tyr and Asp in the filter sequence of TVGYGD, that participate in interactions central to stabilizing the K+ channel selectivity filter. By using protein crystallography and channel electrophysiology, we demonstrate that the K+ channel filter exists as an energetically strained structure and requires these key protein interactions working in concert to hold the filter in the precisely defined four-sited configuration that is essential for selective K+ permeation. Disruption of either interaction, as tested on both the NaK2K and eukaryotic Kv1.6 channels, can reduce or completely abolish K+ selectivity and in some cases may also lead to channel inactivation due to conformational changes at the filter. Additionally, on the scaffold of NaK we recapitulate the protein interactions found in the filter of the Kir channel family, which uses a distinct interaction network to achieve similar stabilization of the filter.

Original publication

DOI

10.1073/pnas.1111688108

Type

Journal article

Journal

Proceedings of the National Academy of Sciences

Publication Date

2011

Volume

108

Pages

16634 - 16639