4R8C
Crystal Structure of CNG mimicking NaK-ETPP mutant in complex with Rb+
Summary for 4R8C
Entry DOI | 10.2210/pdb4r8c/pdb |
Related | 3K0D 3K0G 4R50 4R6Z 4R7C 4R8B 4RAI 4RAR |
Descriptor | Potassium channel protein, RUBIDIUM ION, (4S)-2-METHYL-2,4-PENTANEDIOL, ... (5 entities in total) |
Functional Keywords | alpha helical membrane protein, chimera channel, transport protein |
Biological source | Bacillus cereus ATCC 14579 |
Total number of polymer chains | 2 |
Total formula weight | 22752.94 |
Authors | De March, M.,Napolitano, L.M.R.,Onesti, S. (deposition date: 2014-09-01, release date: 2015-07-01, Last modification date: 2023-09-20) |
Primary citation | Napolitano, L.M.,Bisha, I.,De March, M.,Marchesi, A.,Arcangeletti, M.,Demitri, N.,Mazzolini, M.,Rodriguez, A.,Magistrato, A.,Onesti, S.,Laio, A.,Torre, V. A structural, functional, and computational analysis suggests pore flexibility as the base for the poor selectivity of CNG channels. Proc.Natl.Acad.Sci.USA, 112:E3619-E3628, 2015 Cited by PubMed Abstract: Cyclic nucleotide-gated (CNG) ion channels, despite a significant homology with the highly selective K(+) channels, do not discriminate among monovalent alkali cations and are permeable also to several organic cations. We combined electrophysiology, molecular dynamics (MD) simulations, and X-ray crystallography to demonstrate that the pore of CNG channels is highly flexible. When a CNG mimic is crystallized in the presence of a variety of monovalent cations, including Na(+), Cs(+), and dimethylammonium (DMA(+)), the side chain of Glu66 in the selectivity filter shows multiple conformations and the diameter of the pore changes significantly. MD simulations indicate that Glu66 and the prolines in the outer vestibule undergo large fluctuations, which are modulated by the ionic species and the voltage. This flexibility underlies the coupling between gating and permeation and the poor ionic selectivity of CNG channels. PubMed: 26100907DOI: 10.1073/pnas.1503334112 PDB entries with the same primary citation |
Experimental method | X-RAY DIFFRACTION (2.5 Å) |
Structure validation
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