4X8A

NavMS pore and C-terminal domain grown from protein purified in LiCl

Summary for 4X8A

• Entry DOI: 10.2210/pdb4x8a/pdb
• Related: 3ZJZ 4CBC 4X87 4X88 4X89
• Descriptor: Ion transport protein, HEGA-10, NONAETHYLENE GLYCOL, ... (5 entities in total)
• Functional Keywords: transport protein, selectivity filter, membrane protein
• Biological source: Magnetococcus sp. (strain MC-1)
• Total number of polymer chains: 4
• Total formula weight: 70601.87

Authors

Naylor, C.E.,Bagneris, C.,Wallace, B.A. (deposition date: 2014-12-10, release date: 2016-03-09, Last modification date: 2024-05-08)

Primary citation

Naylor, C.E.,Bagneris, C.,DeCaen, P.G.,Sula, A.,Scaglione, A.,Clapham, D.E.,Wallace, B.A.
Molecular basis of ion permeability in a voltage-gated sodium channel.
Embo J., 35:820-830, 2016

PubMed Abstract: Voltage-gated sodium channels are essential for electrical signalling across cell membranes. They exhibit strong selectivities for sodium ions over other cations, enabling the finely tuned cascade of events associated with action potentials. This paper describes the ion permeability characteristics and the crystal structure of a prokaryotic sodium channel, showing for the first time the detailed locations of sodium ions in the selectivity filter of a sodium channel. Electrostatic calculations based on the structure are consistent with the relative cation permeability ratios (Na(+) ≈ Li(+) ≫ K(+), Ca(2+), Mg(2+)) measured for these channels. In an E178D selectivity filter mutant constructed to have altered ion selectivities, the sodium ion binding site nearest the extracellular side is missing. Unlike potassium ions in potassium channels, the sodium ions in these channels appear to be hydrated and are associated with side chains of the selectivity filter residues, rather than polypeptide backbones.

PubMed: 26873592
DOI: 10.15252/embj.201593285

Experimental method

X-RAY DIFFRACTION (3.02 Å)