@article{ace246988dec419da5d742ea894f84b4,
title = "Structure of the Native Muscle-type Nicotinic Receptor and Inhibition by Snake Venom Toxins",
abstract = "The nicotinic acetylcholine receptor, a pentameric ligand-gated ion channel, converts the free energy of binding of the neurotransmitter acetylcholine into opening of its central pore. Here we present the first high-resolution structure of the receptor type found in muscle-endplate membrane and in the muscle-derived electric tissues of fish. The native receptor was purified from Torpedo electric tissue and functionally reconstituted in lipids optimal for cryo-electron microscopy. The receptor was stabilized in a closed state by the binding of α-bungarotoxin. The structure reveals the binding of a toxin molecule at each of two subunit interfaces in a manner that would block the binding of acetylcholine. It also reveals a closed gate in the ion-conducting pore, formed by hydrophobic amino acid side chains, located ∼60 {\AA} from the toxin binding sites. The structure provides a framework for understanding gating in ligand-gated channels and how mutations in the acetylcholine receptor cause congenital myasthenic syndromes. Rahman et al. report the high-resolution single-particle cryo-EM structure of a native muscle-type nicotinic acetylcholine receptor from the Torpedo electric ray, in complex with α-bungarotoxin from the banded krait. The structure was obtained in a lipidic environment shown to support channel function and reveals a closed, hydrophobic ion channel gate.",
keywords = "Cys-loop receptor, Torpedo, acetylcholine receptor, cryo-EM, ion channel structure, ligand-gated ion channel, membrane protein, nicotinic receptor, toxin, α-bungarotoxin",
author = "Rahman, {Md Mahfuzur} and Jinfeng Teng and Worrell, {Brady T.} and Noviello, {Colleen M.} and Myeongseon Lee and Arthur Karlin and Stowell, {Michael H.B.} and Hibbs, {Ryan E.}",
note = "Funding Information: Single-particle cryo-EM grids were screened at the University of Texas Southwestern Medical Center Cryo-Electron Microscopy Facility, which is supported by the CPRIT Core Facility Support Award RP170644. We thank Craig Yoshioka for cryo-EM data collection at the PNCC under user proposal 50839 and Guipeun Kang for assistance with lipid reconstitution experiments. A portion of this research was supported by NIH grant U24GM129547 and performed at the PNCC at OHSU and accessed through EMSL (grid.436923.9), a DOE Office of Science User Facility sponsored by the Office of Biological and Environmental Research. Initial samples from the affinity column were screened at University of Colorado Boulder EM Services Core Facility. This work was supported by grants from the NIH (DA037492, DA042072, and NS095899 to R.E.H. and AG061829 to M.H.B.S.) and the MCDB Neurodegenerative Disease Fund to M.H.B.S. M.M.R. performed the sample preparation and data processing for cryo-EM, structural analysis, and drafted the manuscript with guidance from R.E.H. J.T. performed the electrophysiology. C.M.N. performed cryo-EM analysis at UT Southwestern. B.T.W. performed the affinity reagent chemical synthesis and M.L. and M.H.B.S. validated its performance. M.H.B.S. and R.E.H. assisted in model validation and directed the project. R.E.H. M.H.B.S. and M.M.R. revised the manuscript with input from A.K. and all other authors. The authors declare no competing interests. Funding Information: Single-particle cryo-EM grids were screened at the University of Texas Southwestern Medical Center Cryo-Electron Microscopy Facility, which is supported by the CPRIT Core Facility Support Award RP170644 . We thank Craig Yoshioka for cryo-EM data collection at the PNCC under user proposal 50839 and Guipeun Kang for assistance with lipid reconstitution experiments. A portion of this research was supported by NIH grant U24GM129547 and performed at the PNCC at OHSU and accessed through EMSL (grid.436923.9), a DOE Office of Science User Facility sponsored by the Office of Biological and Environmental Research. Initial samples from the affinity column were screened at University of Colorado Boulder EM Services Core Facility. This work was supported by grants from the NIH ( DA037492 , DA042072 , and NS095899 to R.E.H. and AG061829 to M.H.B.S.) and the MCDB Neurodegenerative Disease Fund to M.H.B.S. Publisher Copyright: {\textcopyright} 2020 Elsevier Inc.",
year = "2020",
month = jun,
day = "17",
doi = "10.1016/j.neuron.2020.03.012",
language = "English (US)",
volume = "106",
pages = "952--962.e5",
journal = "Neuron",
issn = "0896-6273",
publisher = "Cell Press",
number = "6",
}