3ZJZ

Open-form NavMS Sodium Channel Pore (with C-terminal Domain)

Summary for 3ZJZ

• Entry DOI: 10.2210/pdb3zjz/pdb
• Descriptor: ION TRANSPORT PROTEIN, HEGA-10, DODECAETHYLENE GLYCOL, ... (5 entities in total)
• Functional Keywords: transport protein, selectivity filter, membrane protein
• Biological source: MAGNETOCOCCUS MARINUS MC-1
• Total number of polymer chains: 4
• Total formula weight: 70618.85

Authors

Bagneris, C.,Naylor, C.E.,Wallace, B.A. (deposition date: 2013-01-21, release date: 2013-10-02, Last modification date: 2023-12-20)

Primary citation

Bagneris, C.,Decaen, P.G.,Hall, B.A.,Naylor, C.E.,Clapham, D.E.,Kay, C.W.M.,Wallace, B.A.
Role of the C-Terminal Domain in the Structure and Function of Tetrameric Sodium Channels.
Nat.Commun., 4:2465-, 2013

PubMed Abstract: Voltage-gated sodium channels have essential roles in electrical signalling. Prokaryotic sodium channels are tetramers consisting of transmembrane (TM) voltage-sensing and pore domains, and a cytoplasmic carboxy-terminal domain. Previous crystal structures of bacterial sodium channels revealed the nature of their TM domains but not their C-terminal domains (CTDs). Here, using electron paramagnetic resonance (EPR) spectroscopy combined with molecular dynamics, we show that the CTD of the NavMs channel from Magnetococcus marinus includes a flexible region linking the TM domains to a four-helix coiled-coil bundle. A 2.9 Å resolution crystal structure of the NavMs pore indicates the position of the CTD, which is consistent with the EPR-derived structure. Functional analyses demonstrate that the coiled-coil domain couples inactivation with channel opening, and is enabled by negatively charged residues in the linker region. A mechanism for gating is proposed based on the structure, whereby splaying of the bottom of the pore is possible without requiring unravelling of the coiled-coil.

PubMed: 24051986
DOI: 10.1038/NCOMMS3465

Experimental method

X-RAY DIFFRACTION (2.92 Å)