@article {65626,
	title = {Employing NaChBac for cryo-EM analysis of toxin action on voltage-gated Na+ channels in nanodisc},
	journal = {Proceedings of the National Academy of Sciences of the U.S.A.},
	volume = {117},
	year = {2020},
	month = {2020 Jun 23},
	pages = {14187-93},
	abstract = {<p>NaChBac, the first bacterial voltage-gated Na+\&nbsp;(Nav) channel to be characterized, has been the prokaryotic prototype for studying the structure{\textendash}function relationship of Nav\&nbsp;channels. Discovered nearly two decades ago, the structure of NaChBac has not been determined. Here we present the single particle electron cryomicroscopy (cryo-EM) analysis of NaChBac in both detergent micelles and nanodiscs. Under both conditions, the conformation of NaChBac is nearly identical to that of the potentially inactivated NavAb. Determining the structure of NaChBac in nanodiscs enabled us to examine gating modifier toxins (GMTs) of Nav\&nbsp;channels in lipid bilayers. To study GMTs in mammalian Nav\&nbsp;channels, we generated a chimera in which the extracellular fragment of the S3 and S4 segments in the second voltage-sensing domain from Nav1.7 replaced the corresponding sequence in NaChBac. Cryo-EM structures of the nanodisc-embedded chimera alone and in complex with HuwenToxin IV (HWTX-IV) were determined to 3.5 and 3.2 {\r A} resolutions, respectively. Compared to the structure of HWTX-IV{\textendash}bound human Nav1.7, which was obtained at an overall resolution of 3.2 {\r A}, the local resolution of the toxin has been improved from \~{}6 to \~{}4 {\r A}. This resolution enabled visualization of toxin docking. NaChBac can thus serve as a convenient surrogate for structural studies of the interactions between GMTs and Nav\&nbsp;channels in a membrane environment.</p>
},
	issn = {0027-8424},
	doi = {10.1073/pnas.1922903117},
	url = {http://www.pnas.org/lookup/doi/10.1073/pnas.1922903117https://syndication.highwire.org/content/doi/10.1073/pnas.1922903117},
	author = {Gao, Shuai and Valinsky, William C. and On, Nguyen Cam and Houlihan, Patrick R. and Qu, Qian and Liu, Lei and Pan, Xiaojing and Clapham, David E. and Yan, Nieng}
}
