Role of the C-Terminal Domain in the Structure and Function of Tetrameric Sodium Channels.Bagneris, C., Decaen, P.G., Hall, B.A., Naylor, C.E., Clapham, D.E., Kay, C.W.M., Wallace, B.A.
(2013) Nat.Commun. 4: 2465
- PubMed: 24051986
- DOI: 10.1038/ncomms3465
- Also Cited By: 5HVX, 5HVD, 5BZB, 4X8A, 4X89, 4X88, 4PA9, 4PA7, 4PA6, 4PA4, 4PA3, 4P9P, 4P9O, 4P30, 4P2Z, 4OXS, 4CBC
- PubMed Abstract:
- Structure of a Bacterial Voltage-Gated Sodium Channel Pore Reveals Mechanisms of Opening and Closing.
Mccusker, E.C.,Bagneris, C.,Naylor, C.E.,Cole, A.R.,D'Avanzo, N.,Nichols, C.G.,Wallace, B.A.
(2012) Nat.Commun. 3: 1102
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 stru ...
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.
1] School of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck College, University of London, London WC1E 7HX, UK .