5xsy
Structure of the Nav1.4-beta1 complex from electric eel
Structural highlights
FunctionSCNA_ELEEL Mediates the voltage-dependent sodium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a sodium-selective channel through which Na(+) ions may pass in accordance with their electrochemical gradient.[1] Publication Abstract from PubMedVoltage-gated sodium (Nav) channels initiate and propagate action potentials. Here, we present the cryo-EM structure of EeNav1.4, the Nav channel from electric eel, in complex with the beta1 subunit at 4.0 A resolution. The immunoglobulin domain of beta1 docks onto the extracellular L5I and L6IV loops of EeNav1.4 via extensive polar interactions, and the single transmembrane helix interacts with the third voltage-sensing domain (VSDIII). The VSDs exhibit "up" conformations, while the intracellular gate of the pore domain is kept open by a digitonin-like molecule. Structural comparison with closed NavPaS shows that the outward transfer of gating charges is coupled to the iris-like pore domain dilation through intricate force transmissions involving multiple channel segments. The IFM fast inactivation motif on the III-IV linker is plugged into the corner enclosed by the outer S4-S5 and inner S6 segments in repeats III and IV, suggesting a potential allosteric blocking mechanism for fast inactivation. Structure of the Nav1.4-beta1 Complex from Electric Eel.,Yan Z, Zhou Q, Wang L, Wu J, Zhao Y, Huang G, Peng W, Shen H, Lei J, Yan N Cell. 2017 Jul 27;170(3):470-482.e11. doi: 10.1016/j.cell.2017.06.039. Epub 2017 , Jul 20. PMID:28735751[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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