3TCU

Crystal Structure of NaK2K Channel D68E Mutant

Summary for 3TCU

• Entry DOI: 10.2210/pdb3tcu/pdb
• Related: 3OUF 3T4D 3T4Z
• Descriptor: Potassium channel protein, POTASSIUM ION (3 entities in total)
• Functional Keywords: membrane protein, ion channel
• Biological source: Bacillus cereus
• Total number of polymer chains: 2
• Total formula weight: 21884.18

Authors

Sauer, D.B.,Zeng, W.,Raghunathan, S.,Jiang, Y. (deposition date: 2011-08-09, release date: 2011-10-05, Last modification date: 2024-02-28)

Primary citation

Sauer, D.B.,Zeng, W.,Raghunathan, S.,Jiang, Y.
Protein interactions central to stabilizing the K+ channel selectivity filter in a four-sited configuration for selective K+ permeation.
Proc.Natl.Acad.Sci.USA, 108:16634-16639, 2011

PubMed Abstract: 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 K(v)1.6 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.

PubMed: 21933962
DOI: 10.1073/pnas.1111688108

Experimental method

X-RAY DIFFRACTION (1.75 Å)