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-Structure paper
タイトル | Helical jackknives control the gates of the double-pore K uptake system KtrAB. |
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ジャーナル・号・ページ | Elife, Vol. 6, Year 2017 |
掲載日 | 2017年5月16日 |
著者 | Marina Diskowski / Ahmad Reza Mehdipour / Dorith Wunnicke / Deryck J Mills / Vedrana Mikusevic / Natalie Bärland / Jan Hoffmann / Nina Morgner / Heinz-Jürgen Steinhoff / Gerhard Hummer / Janet Vonck / Inga Hänelt / |
PubMed 要旨 | Ion channel gating is essential for cellular homeostasis and is tightly controlled. In some eukaryotic and most bacterial ligand-gated K channels, RCK domains regulate ion fluxes. Until now, a single ...Ion channel gating is essential for cellular homeostasis and is tightly controlled. In some eukaryotic and most bacterial ligand-gated K channels, RCK domains regulate ion fluxes. Until now, a single regulatory mechanism has been proposed for all RCK-regulated channels, involving signal transduction from the RCK domain to the gating area. Here, we present an inactive ADP-bound structure of KtrAB from , determined by cryo-electron microscopy, which, combined with EPR spectroscopy and molecular dynamics simulations, uncovers a novel regulatory mechanism for ligand-induced action at a distance. Exchange of activating ATP to inactivating ADP triggers short helical segments in the K-translocating KtrB dimer to organize into two long helices that penetrate deeply into the regulatory RCK domains, thus connecting nucleotide-binding sites and ion gates. As KtrAB and its homolog TrkAH have been implicated as bacterial pathogenicity factors, the discovery of this functionally relevant inactive conformation may advance structure-guided drug development. |
リンク | Elife / PubMed:28504641 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 6.6 Å |
構造データ | EMDB-3450: |
由来 |
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