title: Structure of a bacterial voltage-gated sodium channel pore reveals mechanisms of opening and closing.
abstract: Voltage-gated sodium channels are vital membrane proteins essential for electrical signalling; in humans, they are key targets for the development of pharmaceutical drugs. Here we report the crystal structure of an open-channel conformation of NavMs, the bacterial channel pore from the marine bacterium Magnetococcus sp. (strain MC-1). It differs from the recently published crystal structure of a closed form of a related bacterial sodium channel (NavAb) by having its internal cavity accessible to the cytoplasmic surface as a result of a bend/rotation about a central residue in the carboxy-terminal transmembrane segment. This produces an open activation gate of sufficient diameter to allow hydrated sodium ions to pass through. Comparison of the open and closed structures provides new insight into the features of the functional states present in the activation cycles of sodium channels and the mechanism of channel opening and closing.
authors.affiliation: Department of Crystallography, Institute of Structural and Molecular Biology, Birkbeck College, University of London, Malet Street, London WC1E 7HX, UK.
authors.forename: Emily C
authors.initials: EC
authors.lastname: McCusker
authors.forename: Claire
authors.initials: C
authors.lastname: Bagnéris
authors.forename: Claire E
authors.initials: CE
authors.lastname: Naylor
authors.forename: Ambrose R
authors.initials: AR
authors.lastname: Cole
authors.forename: Nazzareno
authors.initials: N
authors.lastname: D'Avanzo
authors.forename: Colin G
authors.initials: CG
authors.lastname: Nichols
authors.forename: B A
authors.initials: BA
authors.lastname: Wallace
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism*; D002942:Circular Dichroism; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D061566:Voltage-Gated Sodium Channels / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D061566:Voltage-Gated Sodium Channels