3T2M: Crystal Structure Of Nak Channel N68d Mutant

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.
PDB ID: 3T2MDownload
MMDB ID: 94071
PDB Deposition Date: 2011/7/22
Updated in MMDB: 2011/10
Experimental Method:
x-ray diffraction
Resolution: 1.95  Å
Source Organism:
Similar Structures:
Biological Unit for 3T2M: tetrameric; determined by author and by software (PISA)
Molecular Components in 3T2M
Label Count Molecule
Proteins (4 molecules)
Potassium Channel Protein
Molecule annotation
Chemicals (12 molecules)
* Click molecule labels to explore molecular sequence information.

Citing MMDB